Aquaponics for Homesteading Part 3: Recirculating Aquaponic Systems and Water Quality

Mar 11, 2021 18:52 · 10315 words · 49 minute read

for over 27 years we’ve been doing a series of zoom programs here for last several months this is part of our series what we call uh aquaculture for homesteading rural and urban this is our third session in this series there’s only four sessions up and running for this today we’re going to talk about recirculating aquaculture systems and dr schwartz down at hampton roads seafood lab uh we’ll be presenting the first paper uh powerpoint presentation today on ras the ends and workings of it and when he’s done i will be presenting a a powerpoint presentation on water quality and some fish health looking at both types of systems aquaponics as well as hydroponic uh aquaponics and recirculating aquaculture systems so you know since we’re getting started i appreciate everybody coming on we have a chat box please put questions into it we will be monitoring these uh chat uh box for questions and if we see some pertinent questions come up we will refer it back to the speaker but basically if these questions can wait till the end of the speaker to be answered we have one hour for our presentation but if necessary we will always go over that one hour mark we used to run these for our two hours before that’s too long so we shorten these uh talks down to one hour blocks and we’re doing this in fact we do this every tuesday at 10 o’clock and we got uh probably five more presentations to go in this block but we have a the fourth session in this series on homesteading for aquaculture will be taking place a week from today we’re going to be talking about feed fishing marketing and food safety so with that introduction uh we got a short time ahead of us i’m going to turn it over to mike for his presentation on recirculating aquaculture all right sounds good david thanks for the intro uh can everybody see a recircling aquaculture system slide covering the whole screen yes sir all right we got we’ve got the right one all right well yeah as david mentioned uh we’ll be talking about uh recirculating systems uh again these systems can be used for hydroponics aquaponics straight up aquaculture we’re really just talking about the system that’s uh you know turning the water reusing the water let’s see this does not want to advance there we go so what are recirculating systems again just to help a little bit with terminology um we consider it a recirculating system when we recycle or reuse 90 percent or more of the water uh on a daily basis so you know if it’s a thousand gallon tank and if you use less than 100 gallons of new water a day we can consider it recirculating and if we’re dealing with something like hydroponics we’re generally just dealing with loss from evaporation and from the water that the plants take out so you’re really just make doing makeup water you’re not even exchanging water um but again just to kind of give us the perspective of where we’re going and if we look at carrying capacity for fish in recirculating systems we have a range of really anywhere from zero to about one pound per gallon of water um we’ll be talking about some different types of systems but uh as the pounds per gallon goes up the systems get very complicated very expensive uh an average would be about a third of a pound of fish per gallon of water so a ten thousand gallon tank would give us uh about three thousand pounds of fish at market time so again just to kind of give us a ballpark but again a less intensive system you know you could have a thousand pounds and ten thousand gallons really depends on how you design the system and how much you want out of it um why do people look at recirculating aquaculture systems they really fall into what’s called controlled environmental agriculture um there’s there’s a lot of advantages uh these systems are generally indoors so we have you know really good animal security we can keep pests out pathogens neighbors that want some of our fish maybe you know if they’re in a building and the door’s locked nobody’s getting in so it gives us good security um we’re really independent from weather um high temperatures freezing temperatures um you know times if fish and ponds sometimes you won’t be able to harvest because maybe it’s been raining for two or three days and you’re you know your levees are muddy or what have you or it’s too cold and you can’t seine the fish well these they’re indoor tanks temperatures are maintained so we can keep production and marketing really to whenever we want to meet something out of the systems and they tend to as compared to surface water systems these recirculating systems have a low dependency on natural resources which is land and water you know again we can put it inside a building so you know those are the reasons we see a lot of people moving into recirc systems um but with advantages there’s disadvantages and by far these are the most expensive systems to build and operate um so those are things you have to take into account uh when you’re gonna get into or thinking about getting into recirculating aquaculture system production um you know be looking at your business plans or maybe you’re counting your dollars closely on what you’re putting in and what you expect to get out and cooperative extension can help you with the business plans also there’s intensified biological risk and this is whether you’re doing plants whether you’re doing fish or shrimp or what have you we’re putting more animals in plants in a smaller area and just by the way nature operates when we put things in close proximity there’s a chance for diseases or pathogens to spread and to spread quickly and also this animals themselves will put loadings on the system which we’ll talk a little bit more about which are called biological uh loading such as ammonia and nitrites and we’ll talk about some things like that so again advantages and disadvantages um it’s good to be aware of them it helps you plan if this is a direction you want to go and if so some of the things that are following here will be you know helpful for you um these are the areas that we’re going to talk about uh that are the components of recirculating systems uh so we’ll just kind of go into each one briefly and then i’ve added a poster on the end that we’ll spend a little bit of time on as well so the culture vessel if you’re going to be doing you know uh fish uh probably more important for shrimp they’re looking for surface area bottom space or vertical things they can hang on fish swim so the shape of the tanks are very important um either for letting the fish swim turn we want the tanks to be self-cleaning we’re going to talk a little bit about solids you don’t want solids just collecting on the bottom of the tank and then you have to go in and vacuum it out it adds a lot of labor while the solids are in the tank they leach and create water quality issues uh so we’ll look a little bit about self-cleaning characteristics of the tanks which is very important sir i’ve noticed that yeah that takes a little bit of planning on the self-cleaning characteristics yes it does yeah that takes a little thought so we’ll give you a couple ideas on the next slide and then the species being cultured again if you’re gonna raise something like a rainbow trout those fish tend to swim forward uh they’re long uh and relatively skinny compared to a perch or a tilapia so something like a trout needs to be able to swim in circles a tilapia can stop turn it runs into a corner he just turns around and it’s not a problem for him so let’s just kind of look at really the three types of uh or categories of tanks that we have uh of course the round tank is probably the most common uh can everybody see my mouse spinning around in the blue circle yes sir okay so this is a round tank and here you got the water coming from the system and so the water just kind of spins around while what happens in here just like it does at your pool at home uh the solids that will settle will collect right in the middle of the tank so this is where we remove the water to go to the filtration system to come back in so this is a very well designed self-cleaning design and it’s one of the reasons people use round tanks now one of the issues with round tanks is we’re putting these tanks inside buildings and the square footage in your building has a cost you can only put so many tanks in the building uh the building has its own heating cooling construction depreciation what have you so people have gone to four-sided six-sided eight-sided tanks but rounding the corner so fish don’t get stuck this rounded corner hybrid still allows for good cleaning no solids collection in the corners but gives you about 31 percent more tank space on for the floor space of the building so that’s really helpful it basically lets you hold more water in the same square footage in the building um we can look at a plug flow raceway uh common in the trout industry where water flows from out of a spring into one raceway runs into the next raceway into the next raceway and then after four five six of these it goes back into a pond or the stream or wherever it goes um people try to gravitate towards these because they can find these but as you can see these don’t circulate the water comes from here goes out here so you have really good water quality here and then it gets worse and worse and worse and worse and by the time you get down here you got very poor water quality well a solution for this is if you have this type of a tank is you can build a d ended raceway uh it’s basically the plug flow raceway with half a circle on each end and then you put a wall from the bottom of the tank to the water surface or above and again here we see the water coming from the filtration system bringing it at an angle and this water is going to spin round and round and round and round all day all night nice flow fish can swim in it with it against it no corners to get stuck in and on these the places to pull the solids for self-cleaning are on the downstream side of the wall where there’s an eddy so the solids will collect here they will collect here or you can put a screen on the bottom and have a discharge on the bottom of the tank so that the solids fall to the bottom of the tank as they come down and then they get pulled out here so you got three points that you can pull solids out again to be self-cleaning and so probably whatever you guys will come up with will be some combination of these shapes but most importantly keep in mind self-cleaning and if the fish need to be able to swim without corners so let’s talk a little bit about solids um this is another problem with recirculating systems again if fish are in cages or in ponds fish waste or uneaten feed just goes to the bottom of the pond or blows to the side of the pond and kind of goes away but in recirc systems any solids in the system stay in the system until you take them out um basically uh fish waste fish feces and uneaten feed are the are the main sources of your uh of your solids but the problems are until we get the solids out of the system the longer they stay in the more they degrade water quality so they affect the health of the water which affects the health of the fish since these solids are organic in nature it increases bacterial loading there’s more bacteria with more solids and these can be bacteria that cause diseases or illnesses the solids are organic so they use oxygen which competes for the fish and we’ll talk about uh oxygen in your system and then very importantly depending upon the fish species you raise some fish are insensitive or cannot handle solids in the water column and a trout is a perfect example if you have a lot of suspended solids and fine particulates that you see if you beaker out some water look at the water the gills of the trout will very quickly get infected and you’ll be calling dr crosby because you have sick fish or dying fish and you might think well it’s a disease but it’s really being caused by an environmental problem which is your suspended solids if you’re growing something like a tilapia they’ll probably eat those and pull some nutrition out of them so the types of systems that you put in uh and the degree that you need to clean the water will also depend upon the types of fish that you’re gonna raise and we’ll look at those here but kind of the simple types of filters that you may be looking at uh for your systems this here is a sand filter that’s just a regular pool filter and they work well for low loaded systems lower temperature systems the problem with sand filters is they’ll tend to cake and when you back wash they don’t backwash properly from the organics but people do use these you can open them up and clean the sand manually once in a while between backwashes you can build swirl separators or radial flow separators you can look these up online a little bit if you want you can easily build these at home and they work very well uh and they just use passive gravity flow in and out uh so there’s no actual media um solids just collect in each of these on the bottom and then we can drain it out this would be a drop filter or a bead filter this is getting more into the commercial types of filters that you can buy um work very well they all work a little bit differently um but this is when you’re starting to buy equipment off the internet these are the types of things that you’ll find for for solids removal uh in aquaculture systems we need to talk a little bit about biological filtration we already had a little discussion about that uh with some folks before this started all the animals that we produce as they feed and metabolize they all produce ammonia which is toxic at very low levels remember the fish live in the environment that they excrete their wastes in so in a pond or in a stream we have low densities of animals and we just have natural bacteria that clean everything everything in a recirculating system is more concentrated so we have to actually build biological filters which really just provides surface area for aerobic bacteria that will convert ammonia to nitrite and nitrite to nitrate and we would test for these all on a daily basis to monitor the health of the system because this is really what drives the health of the animals how many animals you can hold and thus how much feed you put in which is what produces the uh ammonia nitrite so this is like the heartbeat of your system and you want to monitor this very closely also note it’s aerobic so this is also an oxygen demand on your system and we’ll look at that next here’s another design of a biological filter this is a rotating biological contactor again it’s air driven or water driven with paddle wheels in the middle and this just kind of spur turns maybe once a minute and the bacteria go in the water get ammonium nitrite then they come out of the water use some atmospheric oxygen and they do this conversion low tech low cost to operate you can get into more commercial systems that are called mixed bed bioreactors or fluidized beds um they work very efficiently they have very high uh ammonia and nitrite removal rates and it’s basically just a tank that you aerate so it bubbles and these types of media just kind of float up and down and boil like spaghetti and the bacteria will adhere on the surfaces of this and do all of your nitrification so this is the ins and outs of your biological filters their efficiency is based upon uh surface area per volume so the higher the surface area per unit volume the more effective your bio filter should be just like a tank just like your fish tank you want to make sure your biological filters are self-cleaning and not collecting solids so in this case here you’ll have your aerators all the way on the bottom so you don’t get a dead space where solids can collect you want your biofilters also to be self-cleaning just like your fish tanks solids should only collect in your solids collection devices some do both they collect solids and do nitrification this is an example here of a uh bubble bead filter you can buy these online here’s an inside picture the dirty water comes in from the fish tank it goes through here the solids collect on the beads um as the water goes through the beads there’s also bacteria so it converts the ammonia to nitrite to nitrate and then it leaves the problem with these is the solids collect on top of the bacteria so this biofilter does not work the same between backwashes it goes from really clean and effective after you backwash to probably less than half active area by the time you have to backwash it again so be careful on your calculations if you use something that removes solids and does biofiltration at the same time it can get you into trouble i would use something like this just for solids removal and then have a biofilter afterwards let’s talk about oxygen whether it’s fish or shrimp they gotta have it uh and as we can see on this slide there’s lots of things that are taking the oxygen out of the water the fish of course are using it or the shrimp whatever we’re growing so that’s a net loss of oxygen we talked about the biofilter being aerobic the bacteria converting the ammonia to nitrite and nitrate use oxygen and we have biological oxygen demand just bacteria that are in the water that are on the solids in the water which is why we want to get rid of those and then also a small amount of chemical oxygen demand which we usually don’t calculate for but these all uh take oxygen out of the water and if you have a very intensive system with lots of fish you can go to lethal conditions literally within minutes of a power failure depending upon your oxygen supply so you have to have emergency backups but oxygen demand it’s very important to understand where it comes from and then here we can look at some of the ways that we get the oxygen back for low tech systems low density systems it’s very simple this is just a regular uh pond aerator that you float between two strings to the side of a tank there’s a propeller under the water it splashes the water into the air and you can see there’s lots of contact and there’s lots of oxygen being transferred by one small maybe a third horsepower uh floating aerator these work very fine in tanks um we can use uh rotary vane air blowers this is a typical one you buy from an online catalog for aquaculture supplies and this just compresses regular air it sucks it in through this filter compresses compresses it here in a rotary vein and then you blow it through air stones in the bottom of the tank very effective keep in mind both of these require electricity which is a cost and the more oxygen you need because you have more fish and you feed more you need more oxygen you have to have bigger aerators or more aerators and then at some point you get to a point where you can’t get enough oxygen from these two and then you end up buying pure oxygen for anybody that’s just getting into aquaculture i would say stay away from systems where you need pure oxygen stick with these types of passive aeration devices but keep the pure oxygen around for emergencies in case you lose power your aerator breaks or something and the nice thing is you can just have an oxygen tank and you can have it on a solenoid where power is on the solenoid is closed and then if the power cuts off the solenoid opens and then you have it already preset with flow meters to your air stones so for the price of a small solenoid if the power goes out your fish tank will automatically get predetermined amounts of pure oxygen while you get your alarm while you drive to the fish barn or wherever you are there’s fairly simple ways to set up emergency aeration before you get people there so just something to think about before your first power failure results in lots of dead animals talk briefly about water movement remember we need to move the water in the tank for the fish we need to move the water in the tank so that the solids go to the uh area where we’re going to pull them out and we need to move the water through the recirculating system so we’ve got to go from the tank to the solids filter to the biological filter so we can use regular impellers these are like pool pumps jacuzzis we can use air lifts again for low density systems an air lift may be a good way the same thing that does aeration can move your water this is just like an airlift in your aquarium the bubble comes in goes up it pulls the water with it and comes out the top and then we have propeller pumps like you use in agriculture uh these produce very high flow rates with very low head very low electrical consumption but they they can only lift the water efficiently probably six to eight inches so it’s a way it’s a way to mechanize an air lift where there’s very low head differentials with these types of pumps here you can pump the water up 10 15 feet 10 15 20 psi keep in mind the more you pressurize the water the higher you pump it the more electricity you’re going to use all the parts we’re talking about on a system you want to keep in mind the operational cost what does it cost you every day to you know supply the electricity how long does the equipment last etcetera and very briefly water disinfection or sterilization uv is very common here the water comes from your recirc system after it’s been polished comes down here and there’s a sleeve in here with a uv bulb the water basically the bacteria and viruses can be killed by the uv and then the clean water here is going to the bio filter so we can do some fairly simple disinfection with different doses of uv protein skimming is a nice way to remove small suspended particles and dissolved organics you can google these online or refer back to this powerpoint which will be made available here’s just some pictures of some small ones that you can buy if this system had a lot of fish in it you see tons of brown bubbles coming out of here going down this tube into your collection bucket and every day you’ll pick out two or three gallons of what looks like the end of your coffee pot after you left it on all day those are very difficult things to filter out but you can very effectively pull them out with protein skimming so something to keep in mind if you have to have really clean water for your fish like for trout and we’re just bouncing through some of the stuff you’ll find online when you look at systems here we’ll just look at a couple of very simple systems here we can see six independent systems each has its own little bead filter in this case we’re using them for solids removal and biological filtration these were low density systems we were doing uh flounder production in again you can see how you can stack them nicely not utilizing the floor very well again this is a recirc environment if this was a production floor you’d want all your tanks very close together just enough space to walk between and harvest so you could put as many tanks as possible into the room but you can see these things stack very nicely we have the rounded corner tanks work very nicely simple designs uh here’s one where they’re producing you can do minnows or fish for the ornamental trade if you want to do angel fish or guppies here the system is all on the bottom we have solids removal biological filter uv sterilization and then the water comes back up into all these tanks so these are all independent tanks individual tanks but they all flow on this main system so we can have different life stages again lots of different ways to do it you can just buy glass aquaria and you can connect them to a system like this very very easy to do and here’s a shot kind of of an integrated aquaponics uh tank here’s where the tilapia or uh perch are in this case then we go through our solids uh filter and biological filter and then it goes up into the plants which of course now we’re going to remove the nitrates and then this is all gravity flow to here gravity flow here and then gravity flow back to your tank one of your rules of thumbs is you only want to pump water once and let design move it through the rest of your systems i think here we think we’re doing lettuce and a few different things so you can see a very very simple very clean system nothing fancy works very well so just in review uh for design considerations are you raising trout or tilapia or catfish or you know what do those fish want and need that’s going to impact the shape design and water flows in your tanks um what life stages if you’re producing fingerling they generally need cleaner water um than adult fish that you’re doing grow out on uh and young fish need more exchange rates again they need super super clean water compared to grow out so life stage is important maybe you’re going to produce fingerling to sell to other farmers well a fingerling system is going to be different than a grow-out system so just kind of keep those in mind where you’re going to do it look at your water sources you know do you have good ground water um is that groundwater does it make it through droughts you know talk to other farmers or people in the area what happens over 10 years when was the last drought were the wells still running good or did the water quality change um you know how how intense do you want to run the systems these are all important to how much water you may use remember we talked about exchange rates and then uh buying the equipment it’s very easy to just buy a turnkey system off the internet problems are you’re probably going to spend a lot of money and then is that equipment that you can get locally serviced at your local garage or local handyman mechanic or maybe that’s you um make sure it’s stuff that you can replace effectively look at your energy costs look at your power demand curves on your pumps and your pressures uh you know it’s the basic gallons and then head pressure so you want to have high gallon low head pressure uh for energy efficiency so always calculate those look at durability serviceability again you don’t want stuff that you know the pumps come out of europe or something which happens and then it’s really expensive to uh to replace or repair if we just want to look at trends um probably the most common one is people are looking for higher value animals particularly smaller producers and they don’t sell into commodity markets they sell into niche markets so if you’re producing trout or tilapia or perch as food fish on a small scale to be economically viable you’re going to try to sell direct to the end consumer whether it’s a restaurant whether it’s somebody that’s going to come by and buy the fish for for their house uh for their fish fry or whatever they’re doing you try to knock out the middlemen so that you retain more of the value and people are always looking for the next high-value species so depending where you are look to see what people are around you look for or the small restaurants the mom and pops you know they’re probably buying cisco or something see if they’re interested and what would they be interested in um again we got lots of different things uh that are being grown in virginia fresh water salt water brackish ornamental doesn’t have to be for food it could be to sell to pet stores or different places could be for stock enhancement here’s some fresh water prawn that were produced here is a bronze farm hybrid stripe bass are a favorite for fresh water recirculating systems and then as promised this is at the end so you will have a copy of this this is kind of a combination of good aquaculture practices for recirc systems here you can see a little bit of some design suggestions on percents of flow rates to different parts of the systems there’s different suggestions for water qualities uh system operations marketing um so again there’s just i found this would be a value to put in it’s part of a series which we put together with david and brian and others uh this one was particular for recirc systems but there’s lots of good common sense things in here uh that would help that will help you as you design or improve your systems so this has been tacked onto the powerpoint that you guys will have available and you can read through it uh later at your convenience and as always you can reach out to any of us uh at virginia cooperative extension or any questions in the future problems uh reach out anytime and okay i’ll hand this back over okay mike and i guess this can be for you and or david but um can let’s see wait hold on let me get back up here can the particulate from protein skimming be used in compost i asked the person if they were just raising fish or if they also plan to use some of that effluent for fertilizing plants and they said both so um can you give us some input absolutely that’s a very good question and the answer is absolutely so long as this isn’t the salt system as long as it’s a fresh water there’s going to be very concentrated fine solids uh as well as nutrients you would want to run these through a either as a soil application or if you’re going to put this into a hydroponics you might want to just run it through a little uh biological reactor to convert everything into nitrates remember a lot of what’s going to be in here is going to be the actual organics that haven’t been broken down yet so the solids you can compost the dissolved solids you can uh you know put into a small reactor and produce lots of nitrogen nitrate but yes there’s a lot of value in that if you’re looking at a sustainable system we’re trying to where you’re trying to keep everything this is concentrating a lot of the stuff that you would want to use if you’re going to grow plants very good question yeah i was going to say mike you know yes is definitely to all this stuff the best thing that is on this system is when you do a decoupled system from a ras to a hydroponics taking the solids and everything else we’ve been doing that with small aquaponics systems on a decoupled uh basis and it works very well you know because it allows you to add fertilizer if you need to to make sure that your plants are growing properly so yes you can do this great stuff for your garden and then there’s another one um are chemicals that are used to remove chlorine or chloroamine from urban water systems that are used in the ras units approved for use in food production systems i’m going to say 99.

9 yes yeah i’ve not seen a circumstance where they’re not yeah and we’ve been using that stuff for years so it’s approved because the probably use those and uh some waste treatment plants some of those chemicals sometimes but um go back to the compost in question if they have extra solids that would probably be ideal to compost and then the effluent or compost tea or whatever you want to call it the uh the tea the that has the fertile the liquid fertilizer in it that you run through the plants then you know that of course can be taken up by the plants i just wanted to clarify that a little bit more yeah yeah and i just backed up to the solids equipment when you backwash these systems you’re going to get a very concentrated solids coming out so that would be very good to go to compost because that’s going to be very heavily solids laden so that’s something you would put into compost in fact uh mike i think you could probably go directly into your garden bed with some of this stuff because it is lots of organic materials to begin with and just work it into your soil well and but some of the raw stuff you want to be very careful uh as far as like from a food safety standpoint too yeah because it’s it’s possible to have fecal coliforms e coli uh it’s possible to have these from different things that may be in your barn maybe a rat ran through at night over the rafters and pooped in the water so composting will take care of all that all right that’s all the questions i see in the chat box i don’t think i’ve missed anything okay okay yeah mark i’m gonna be up next and you got the uh the powerpoint for me please ah there we go okay expand that up if you don’t mind there we go okay thank you uh this section we’re going to cover a little bit about water quality and fish health there’s got to probably be some redundancy but that’s okay uh water quality is one of your most important aspects of raising fish in any kind of system and basically we’re going to be kind of talking a little bit about aquaponics and ras next slide please next slide please okay basically uh aquaponic systems tend to be smaller scale water quality issues can occur in these systems uh you still need to be monitoring the water quality for uh toxic ammonia ph and things of that nature uh but it’s a little bit different than a larger scale next slide please you know a big huge uh ras operation uh their problems gonna be more different and different uh situation different critical things to go affect them more so because the intensity of raising fish trying to get more fish per gallon of water versus aquaponic system which tends to be far less fish per gallon next next slide regardless of uh the situation yet doesn’t matter if you’re raising fishing ponds tanks aquaponics or recirculating aquaculture system fish kills will occur next slide hit the button again and and you don’t want to see fish with x’s on their eyes that means you just lost a lot of money so basically you need to be aware what will kill your fish in these systems next slide just to understand how things work why fish die why we have have problems with diseases and water quality hit the button again hit the button again and hit the button again there we go basically we’re looking at aquaponics ras system we’re looking at the environment you gotta realize we’re using a bio filter we’re actually trying to create an artificial environment to take care of the water quality if the water quality in these systems get bad we also have pathogens there’s pathogens out there and we’ve got hosts our fish so we’ve got these 3 components that are involved in our fish health model if the environment goes bad next slide please go ahead and hit the button a couple of times please we get a disease situation the environment merges the pathogens and hose together to create a disease situation out there or or the water quality gets so bad that we end up with a disease situation so water quality environments drives many of our fish health issues next slide uh again this is going to be our key to uh to our fish health is environmental stress and again we don’t want to see a tank full of dead fish because we ignored our water quality monitoring across for doing this next slide okay the other aspect that’s going to keep our fish healthy and alive and everything else we need to look at what are what is our practices that we’re doing what is our husbandry what is we need to look at having good fish husbandry you know we gotta look at stocking rates you know we’re you know if we got a small aquaponic system we don’t want to try to force a pound per gallon in a system like that so we need to look at those kind of things now how many pounds per gallon we’re trying to push into these systems is critical you know what is our feeding how we’re feeding these fish again feeding is pretty important because feeding is what’s going to deteriorate the water quality of these systems and if again if the water quality uh deteriorates we’re going to have issues and again we got to be looking at our at our bio filters so water quality management feeding rate stocking rates is some of the critical things we want to look at is for having good fish husbandry next slide okay depending on the level of production that you’re trying to do you’re going to probably want to have some kind of water quality test kit whether or not it’s a type that you get down at your aquarium store or where not you go ahead and spray and get yourself a professional water testing kit if you’re doing uh recirculating aquaculture systems you definitely gonna have a decent kit to measure the watercraft and things that we want to look at for testing your hardness alkalinity ph total nitrogen tan even chlorides might be something and temperature and nitrite so these are some of the basic water quality test kits uh parameters that we need you might want to get one that does nitrates too so because you want to know how much nitrates you’re getting into your system that’s going to be good for your plants again these systems can uh you can buy little strips or small test kits that run from 23 dollars all the way up to kits that cost 350 dollars next slide again the artificial ecology is what’s gonna keep your water quality good again mike talked about the bio filter again you notice you got these beads the surface areas is critical more surface areas you have more bacteria is going to grow another thing is make sure that these beads are always moving and not getting clogged if these start getting clogged you’re not going to have a good biofilter next slide again just simplistic picture view of what a biofilter does the fish and feed is going to be ammonia it’s going to be getting ammonia oxidizing bacteria nitrite oxidizing bacteria and we’re going to get nitrates to be used for the plant so we got the bugs on the bio filter the bacteria in the bio filter that’s going to produce the nitrates for the plants next slide a little bit more detail here you know fish waste food excess any kind of organic matter it gets in your system it’s going to be great it’s going to create ammonia problems we’re talking about total nitrogen uh unionized and ionized ammonia unionized ammonia is what toxic to fish and ionized ammonia is not so we gotta watch out how much uh unionized ammonia we have in the system the higher the ph higher temperature more toxic ammonia we have again we got these aerobic bacteria nitrous amonas that produces the nitrates and nitrite no2 can be toxic to fish that can cause some problems too then nitrobacter nitrates you know you got your plants some algae they’re always algae growing somewhere especially if you’ve got a greenhouse and a small aquaponic system and then eventually to nitrogen and then atmosphere next slide again uh just to show you that there’s sometimes a lag time you know you always get your ammonia spikes first then your nitrite then your nitrate and it could take up to two to three weeks for this biofilter really get matured next slide again just looking at the different biofilter medias there’s a lot of them if they get clogged they won’t work so you got to keep an eye on this you know if you’re not getting your solids out of the systems the solids will plug up the biomedia and then you won’t have your artificial ecology or biofilter not working then you go see all sorts of extreme problems with your water quality like ammonia especially ammonia nitrates next next slide oxygen level is very critical so if you’re going to be in this professionally raising fish and recirculating aquaculture system of any kind of intensity it pays to invest into a meter if you’re a small scale operation with a back uh backyard aquaponics system you’re probably not going to need this but you still want to be able to check your water quality for different uh parameters like ammonia ph and stuff like that again if the oxygen levels fall below five in a system you can have some problems once you start hitting around three you’re looking at very lethal uh oxygen levels you know some species are more tolerant tilapia is known to somehow survive lethal levels of low oxygen but not all of them any fish will succumb to low oxygen levels next slide again aeration make sure that you get narration not only to your fish but also into your bio filter next slide again hardness is pretty important if you want these systems to function properly make sure you have adequate levels of calcium in the system some species need hardness in the system and they won’t grow or you will have problems hybrid striped bass is one of these systems i like to see uh hardness at least around 100 parts or better in a system uh calcium chloride works anything calcium carbonate works too anything that you can get calcium into the system because your biofilter and plants gonna need it as well as your fish gonna need calcium in the system so this is something that you would share kind of like basis next slide uh alkalinity this is your carbonates and bicarbonates in the system you can see there’s a strip system you don’t have to spend uh 350 for for a test kit you can buy these strips systems for about 15 dollars and you get anywhere about 50 to 100 strips in a system and that can check your water quality pretty easily we want to be putting sodium bicarbonate this is something i would check on on a daily basis because if your carbonates bicarbonates get very low your system’s not going to work very well uh look at how much feed you’re going you want to add some sodium bicarbonate on a regular basis and i like to maintain at least about 100 parts per million but only it’s also going to help buff for the water for the ph change in the system so we don’t get real high spikes or real low typically in recirculating aquaculture aquaponics systems we always see a drop in ph to low levels and we’ve seen them get down very low we’re not going to see our biological filter operate next slide please ph this is critical uh once you start getting down below seven uh in a system uh your filtering system the bacteria not going to operate plants like lower ph you know ph 6.

5 is probably great for tomatoes but not for the bio filter so we want to look at this look at the ph every day there’s simple systems out there don’t cost a whole lot of money but this is something i would look at every day and see what it’s doing if the ph starts dropping you know that means your biofilter uh needs some more alkalinity in the system to get it going or or you’re going to end up with a biofilter that’s collapsing on you so check this on it every day i don’t expect to see lethal ph in these systems but we do like to see it somewhere in the seven and a half range in these systems next slide okay we talked about water quality earlier about how the biofilter how we go from ammonia to nitrites nitrites is a can be a problem in the system for different species of fish catfish and rainbow trout are very sensitive to nitrites in the system uh tilapia not so much bluegills not so much so the species of fish you’re dealing with will be affected differently for nitrates basically what nitrites do uh the no2 gets into the bloodstream attaches to the hemoglobin and this prevents oxygen molecules attaching which causes a toxicity effect it turns the fish blood brown there’s an example of what what normal blood looks the top picture of catfish is brown and that’s due to nitrite toxicity uh any kind of chlorides in the system will help prevent this toxicity problem happening and it probably will not be enough chlorides to affect your plants common salt is what we use next slide please okay again total ammonia nitrogen this is going to be the killer in your system uh you know you’re putting a lot of organic stuff into the system feed waste and your bio filter is trying to move this for the system into nitrates and nitrogen again it doesn’t take a whole lot of um of ammonia in the system especially the uh the unionized ammonia you know there’s a graph there shows the two types of ammonia in this system as we climb in ph and temperature we get more toxic among which is the hello the unionized next slide okay quickly we’re getting close to the end uh temperature relationships and diseases are quite commonly known certain diseases will grow only at certain temperatures so you know monitoring the temperature of your system is a good idea next slide again depending on your system if you have a large recirculating aquaculture system you definitely want to look at some kind of bio security plan using asset principles to develop it there’s a lot of public occasions right now that’s out there because you don’t want to end up getting some kind of pathogen that results in some kind of quarantine that does happen i’ve known farmers that been quarantined due to pathogens next slide please okay and so basically we want to keep the bugs out not these particular bugs but we want to keep uh fish bugs out next slide again uh a fish this has a wormy life these are just all the little critters that you can find just one species of fish i mean there’s a lot of different parasites a lot of different worms that gets in the fish it’s just matter knowing where to look for them to find them so we want to try to keep some of these problems out of our system next slide okay biosecurity depending on your situation uh we have a situation where all trucks going into the facility go through some kind of disinfectant you know foot baths you know keeping your materials clean uh not using the same net for everything on the farm things of that nature so make sure that on your biosecurity you start with people people is what you got to watch out for that’s the uh controlling factor of biosecurity is limiting people into the system next slide okay here just some simple things disinfected doctor crosby we just lost you well thanks get rid of that fish you know we’re talking about checking water quality things of that nature uh make sure you do this on a daily basis next slide okay uh the other thing we want to be aware of when it comes to any kind of disease situation is look for behavioral changes behavioral changes it’s usually one of the first indication that we’re having a problem feeding behavior swimming behavior some kind of erratic swim behavior fish conjugating around the edge or coming up to the surface doing all this erratic behavior it could be because of ammonia spike in the system the things of that nature so look for behavior if you see a change in behavior there could be a problem with diseases next slide again just to show you that a couple of pieces are common in some of the systems and i’m going to have some tilapia here because everybody thinks tilapia is an invincible fish they’re not they can get sick and they can get diseases here’s a tilapia with some aeromonas lesions that have died from that had an aeromonas infection uh they can get sick from that so that’s one of the bacterial diseases that can’t we actually see aeromonas with and other species of fish in these systems like bluegills so if we get that environmental stress aeromonas is one of the first bacteria that can come in and cause us some problems next slide next slide let’s see there we go um streptococcosis can be a problem for systems especially large recirculating systems we haven’t seen this in small systems we’ve been monitoring doing some surveys of small aquaponics systems and one of the things we’ve been looking for is for streptococcus in these systems one thing that we want to watch out for is one of the problems that strep can do to a system is cause us very uh bad mortality problem which could end up being a complete shutdown and and uh disinfecting the whole system one thing that we want to look out for is uh parasites in the fish giodaculus is a protozoa is a a parasite a motogenic parasite that can get on the gills and skin and there’s a lot of papers and indication that these things have a nice anchor hook system that hurts the epidermis uh makes breaks in the gills that allows for streptococcus in the skin next slide okay uh the the common parasite that we see on these efficiency systems is trichodina which is this protozoan parasite it’s gotta call it the flea of the fish world next slide hit the button there we go and these things can be pretty intense on a fish okay another one to look out for is another protozoan now you can go ahead that’s fine another protozoan we want to look at is ich which is a ciliated protozoan it gets on fish this is something that you would not suspect uh getting it into a system because she got controlled system and fish grow however other species the fish like bluegills there are typically can carry something like this that you stock into into a system uh if you’re stocking in light where the temperatures are below 80 degrees it can form in your system and forgo stock bluegills i tend to stock them uh for the summertime where our temperatures our tanks are going to be above 80.

otherwise you’re going to have to have a start controlling these things as long as water temperature is below 80 degrees so this this stuff can happen even in a recirculating system even though uh ich is one of the things you find in pondfish next slide yeah there’s just a picture of that next slide okay okay what are your contingency plans so you’re having a situation you’re having problems you’re looking at your fish it’s hanging upside down you have to look at the gills and just see tons of parasites all over the place i mean it’s packed in uh at high density so what do you do what about your clients how are you gonna deal with the situation how you go treat this situation who you gonna call who you gonna bring in to take care of the problem uh these are all things that you gotta ask yourself and have some kind of contingency plan to take care of this situation so when you see dead fish popping up so what do you do have a plan next slide please now what do you do you call somebody that knows something about fish uh next slide you know there’s fish health specialists there’s veterinarians out there there’s uh fish health researchers there’s aquaculture specialists that can help you on uh with your problem next slide please there we go next slide let’s just keep going next slide and just because somebody works in fish health doesn’t mean they can’t raise fish again under covid 19 uh we’re not at the farm anymore but we do have phone numbers and we can try to help you out the best we can uh again fish never gets sick during regular office hours we don’t have regular office hours anymore so you know things happen at midnight on saturday night now that’s when problems occur so have a contingency plan have some biosecurity and everything else next slide please okay take home here having a healthy aquatic environment for fish is critical that’s the reason we have water test kits to keep an eye on things like ammonia in the system ph check the alkalinity we want to make sure we have good fish husbandry not trying to stock too many fish in a small aquaponics situation or if we have a large ras system we’re trying to get a lot of fish in there make sure that we have adequate oxygen levels for them test of water quality have some kind of bio security contingency plan next slide and that’s the end we’re a little bit over the hour i kind of went for that fairly quickly but again the point is fish will die we will have water quality problems and you need to be able to deal with the situations as they arise and that’s what we’re here for tell that okay okay any questions okay doc i do have one in the chat box um why is there such a high failure rate of aquaponics operations when they attempt to take them to a larger commercial scale it’s probably uh production costs not being able to produce enough fish you know if i if i was going to a large scale i would just be totally separated i’ll be doing recirculating aquaculture then just uh hydroponics aquaponics is what he things is designed more or less for a small scale more so self-reliant system uh because it’s a low production end it’s very extensive and when you’re trying to raise fish for profit you need to be more intensive because you’re talking about pounds per unit it’s just like if i had a pond and i’m growing fish out there if i got 3 000 pounds per acre and if i can get that up to 3 500 pounds per acre i’m doing a lot better but if you’ve got a small aquaponic system you’re trying to go to eighth of a pound a quarter pound per gallon and trying to push it up to higher uh numbers you’re going to tend to be a failure in that aspect because the system can’t handle it but if i had a recirculating aquaculture system like mike has shown with bead filters you know high-end equipment then i can take that fish up to almost a pound uh and get a better production so we’re talking about extensive versus intensive the the thing with aquaponics is that it’s a cool factor uh you know when you tell you folks you’re raising fish and tanks and doing hydroponics just so so so but soon as you say aquaponics everybody kind of gets the eyes wide open they get high interest and they want to do it it’s a fairly uh unique system but it’s just not capable of really handling the numbers because we need to have production to make money okay okay there’s another one and mark you and doc can answer this one we should they want to know where they can download the slides and we should have those ready what in a couple of days help me mark i mean the videos of this or this the powerpoint i guess they said slides so i don’t know if they want the powerpoint or the whole presentation because i know the presentation will be going online when they get it closed captioned and then they’ll have it on a youtube channel at vsu but if you want this the proper slides if you can just contact dr crosby or somebody we can get them to yeah and some said both please so you know but like i said they will there will be a link uh but it’s gonna take us a few days to get this uploaded and to get the uh closed captions done so please be patient yeah and right now if you really would interest in getting the slides the best way the simplest way is just to go ahead and email me uh and ask for a copy i will make this as a pdf file so it’ll be easy to send to you so you would have it uh for your use to go through it at your leisure the other thing is mark however we’re gonna handle the the evaluations on the qualtrics there you go i have it here is it time now well we’re getting real close to it but let’s let’s ask folks right now a couple questions and they can uh say yes or make it in their comments did you think this was uh uh you got enough information from this little uh one-hour presentation to help you make some decisions and what direction you would like to go and doing uh fish either in grass or in aquaponics you know and if you think so say yes or no yeah i gotta definitely get some good information well good very good uh do you think we need to have more of these more regular you know because this is because right now you know our presentations are pretty uh defined by the time limits that we do and we’ve had some bigger programs on this now the question is always rises how long does does one want to sit in front of a computer to see… .