(Recirculating Aquaculture System)

For those of you that don't know I bring in YOY bluegill and yellow perch hatched in two of my 1/10th acre ponds for the winter to get more growth on them for my small aquaculture niche market.

The cooler ready for YOY fish from the pond. Thanks to Ken's post here (Catmando) I built a cool spray bar for it.



Some of the 725 YOY perch I took out of the yp production pond in August. They were placed into a floating cage in the largest pond until the RAS was ready. I usually wait until October but I was having some D.O. issues with the production pond due to extremely high water temps and an excessive algae bloom this year.



Here's one of my two 300 gallon galvanized stock tanks after I stripped off the old epoxy, removed the rust, acid etched the galvanized surface and repainted with Sweetwater (AES) epoxy primer and epoxy. The black thing in the center is a Uniseal that takes the place of a more expensive bulkhead fitting.



The center drain with a homemade antivortex cover. The 3 inch PVC slides through a Uniseal installed in the tank and connects to a couple which connects to a drain assembly (See next picture). The diffuser is mounted on top of this cover.



The center drain before it connects to the clarifer tank. Note the gate valve. A coupler just under the fish tank and here in the photo allow me to take apart the system for moving if necessary. This is the second tank I have in my basement. This one is for primarily yellow perch, is only 200 gallons, and is made of HDPE.



Here's pic of the drain assembly excluding the fish tank. Not pictured is a hose that connects the other side of the 't' with a ball valve to close it. The end of the hose sits inside my floor drain of my basement that goes to my septic tank.





O.K. here's a pic of two drain lines coming together from two different tanks before going to the floor drain. I also have an end cap on the end of the drain line as a fail safe in case there is a leak in the ball valve. I had a tank drain on me once at night while I was sound asleep. It will never happen again.






Here's a unit identical to one I have in my basement I built and set up for the wife's high school ag classes in their greenhouse. They presently have about 300 4 to 6 inch YOY yellow perch and over 100 bluegills in it. I hatched them and feed trained them in a couple of my ponds. The picture was taken before the RBC (rotating biological contact filter) was covered and the tank was filled. If all goes well they will be planted back into one of my ponds just before the school year ends.

An inverted 'L' that is a spray bar which creates a counter clockwise circular flow. This causes settleable solids to wind their way to the center drain. Know as centrepedal flow or the "tea cup effect." Only problem is it's a fine line between too much flow for the fish and not enough effective movement of the particles. With trout it wouldn't be an issue but more sedentary fish like bluegills and yellow perch it can be.



A view of the spray bar and exit from the RBC tank back to the fish tank. Notice the upturned elbow increases aeration on the return. The spray bar is clamped to a u-tube siphon that strained out suspended solids from the tank. One 30 watt pump runs the entire system minus the 40 watt linear air pump that provides air to two tanks. Also notice the diffuser in the tank with the air line going up. This keeps the airline from restricting the self cleaning action of the tank.




A more close up view of the spray bar assembly and water line hose with the pump which sits on top of the clarifer tank. The ball value allows asjustment of the spray bar intensity and at the same time the amount of flow that goes to the RBC (other end of hose) that turns the RBC.



The RBC and tank without the cover, which keeps it dark for an optimum environment for the bacteria. I have changed from a plastic tarp to two layers of shade cloth to allow it to breath. I was concerned the plastic tarp would restrict oxygen.
The yellow perch tank is on the other side of the unfinished wall and shares the RBC.




Here's my 300 gallon stock tank with some bluegills in it. It doesn't look like it but there are over 100 six to seven inch bluegills in it. I could easily have doubled the number with no problems. They're fed 3 X per day in 75 degree water.



A more close up picture when they were first put in:



Here's my power back up (inverter) and two deep cycle batteries. If I remember right this will run my two pumps (for two tanks) and linear air pump for 16 hours if the power goes out.

Cecil, that is seriously awesome. It all looks great, and the work you put into it really shows. I think I could pull up a chair and watch those BG's all evening. Forget TV.

Those coated stocktanks blow me away.

Thanks for the kind words. It works well but I'm still tweaking it.

Yeah I can relate to watching the fish too. The dog also follows me into the basement to snarf up any pellets that fall on the floor.

Can you give us a cost estimate for the two tank system? You can use a coded message if this information is proprietary (wife-wise)

I'm thinking around $600.00 for all the materials if you have to buy the stock tank which I did not. I would suggest an HDPE stock tank vs. the galvanized tank, as when you consider the not having to purchase the epoxy paint it's cheaper. Also you're not worried about the epoxy not lasting.

Rural King has a 6 foot tank for a little over $200.00, I think. It has to be special ordered and prepaid, and no deliveries during the winter, but there is no shipping charge.

If you build a fluidized bed sand filter or a bioreactor filter you're not only looking at less for the biofilter materials, but you won't have to buy a tank for an RBC and there will be less floor space needed. Then you're talking $450.00 or less.

Not proprietary at all. The wife is good with it as long as I make money, although she is a big believer in hobbies too. The original set up before I made some modifications was from the excellent book Small Scale Aquaculture by Steve VanGorder.

Pretty neat Cecil.

Those tanks look familiar! Cecil, thanks for the pictures. It's coming along well now!

How'd the BG like the flash from the camera?? I know you're keeping it pretty dark in there.

They freak even before the flash when the red light goes on. The flash only compounds it.

Looking good Cecil. The fish look happy!

Do you have your batteries matched the same? ie... same rating, age..., otherwise the life may be shortened. Look into the AGM batteries I was telling you about if you get a chance.

The school is probably quite happy also.

Same exact batteries, brand, rating etc. One is a little newer but the older one hadn't been used and was constantly on a trickle charger.

I may turn the smaller perch tank into a centralized fishless tank for serious aeration and a foam fractionator. I don't like the way the yellow perch swim around and around this smaller deeper tank using up a lot of calories which could effect their growth rate. I think the diffuser causes too much turbulence in this smaller tank of the two. It's not the spray bar itself because I temporarily turned off with no effect. However when I turned it back on and turned off the diffuser may of them slowed down and suspended in the water column which is what I'm more used to. Could have been curiosity or mild concern as to the sudden change. However I'm going to try it longer term monitoring D.O. and see what happens.

The large tank can handle them all and is on the same biofilter anyway. Another advantage is I could make the fishless tank a better remover of suspended solids if no flow is going to it's center drain.

Foam Fractionator?? Sounds like I could use that to prevent spillover, (and sticky countertops), when I pour my Pepsi throwbacks...

VERY impressive! I'd pay you to come set up a couple of those for me. Ever considered being a consultant?

Too much gas their Bruce???

Cecil has a very nice "homegrown rig", and it works for the most part for what he needs, and is trying to accomplish.

Sorry Cecil, consultant level, not anytime soon! But you could be an asset, like at the school, to get peoples feet wet, so to speak.

Have to start somewhere, and jumping off a bridge is a quick drop.

Hope I did not confuse anyone, but all heartfelt intentions to everyone.

Bruce,

Thanks for the kind words but I'm still not there yet as JKB says. I have some bugs to work out. Yes, I have a system that does what I want it to do as in bring fish in for the winter and put a few inches on them, but there is still so much to learn. And the students love it as it's very hands on.

I will be building and trying both a fluidized bed sand filter and low space bioreactor for biofiltraton. Both are cheaper to build than the RBC I have, and have a smaller footprint and more surface area for bacteria. At some point I think I will be using one of those in combination with a rotating drum filter for mechanical filtration when I get my pole building built. When I have the system that really works for me I doubt it will even look like the ones I have now.

But as JKB says there is nothing like the experience of getting your feet wet by raising fish. You can read all the books and publications, and draw up all the blueprints you want but it's amazing what you'll miss if you don't have the responsibility of live fish.

Very nice job Cecil. What kind of growth do you get over winter ?

Last winter I was getting an inch a month with smaller bluegills that were hatched in the fall. Not sure if these larger ones will grow as fast now that they are 6 to 7 inches. But they have some Condello genes so they are good stock.


I do have warmer water this time at 75 F.

Funny but the a foam fractionator is a pretty helpful device that removes DOC (Dissolved Organic Compounds) by creating foam which is discarded of which these dirty compounds attach to. Contrary to popular belief they are not just for saltwater aquarium. They can be easily built too.

Here's a pic of foam coming off of foam fractiontor in a Koi Pond. The poster posted it on a Koi forum after some know it all came on and set there is no way it will work in freshwater. LOL





BTW this is probably the same foam we see on our ponds sometimes after an algae bloom crash or too much feeding. Of course not as concentrated.

Tanks for sharing Cecil.

I'll see that on the windward side of the local lake. Years ago people said it was soap bubbles.........

Thanks for the explanation, Cecil.

Will your system skim, or otherwise remove the foam automatically, or will that require hands on?

Is there a foaming agent involved, or is the foam created by mechanical means?

If it's done chemically, is the foaming agent reusable after the organic compounds have been removed, or is it considered sacrificial and discarded?

Here's a small DIY one made very easily in about 10 minutes. Only uses agitation and aeration provided by two small air stones. You can direct the foam into a bucket or something.

http://www.koiphen.com/forums/showthread.php?55187-DIY-Protein-Skimmer

The big commercial farms use ozone to increase the effectiveness of a foam fractionator (Protein Skimmer).

Cecil IIRC 75 - 77 is the optimum temp for BG feeding and growth.

I found the book (brand new) on Amazon for $2400.00!

Just the book? I have one in my basement. Maybe I should sell it!

I sent one of my spares to esshup. I have seen them as "rare collector items" going for a pile-O-cash. Still have two more that I'll hold on to until the price really jacks up

One of them has a signed "Thank You" note from the author, and was a freebie.

It really is a good book that takes the Heavy Science and Engineering out and makes it easy for someone to get going on a small budget.

SVG did a good job on this!

Steve is also a good guy that will take some of his busy time to answer any questions you may have. And he does consulting on much more complex systems than in the book and is president, I believe, of a fish farm in PA.

However it is worth mentioning the RBC in the book, of which I have built two, was used in Biosphere II.

Last I corresponded with Steve he's not sure he will republish the book or will do a digital version. He is baffled by the prices his book is selling for though. (Original list price is about $25.00.)

That book is a very good piece of reference materail. Thanks JKB!

I got some good information today from Bill Lynch Ohio state extension agent and perch producer extraordinaire. (Where I got my original perch stock from).

I was concerned about my perch swimming around and around with the current of the circular tank. I asked him if he has seen this and if it's normal etc. Here is his response:

Cecil,

Yes I have as we have nothing but circular tanks. They will constantly swim in a circle, speed dependent on water volume flow rate and direction. In food fish perch culture swimming is good as it builds fillets and not body fat. Also limits nipping at each other. They swim the fastest right after being put in a tank and then often slow down a little bit once they get to it. But always in a circle.

Bill

Perhaps a better pic of the bluegills. I was able to eliminate the AIAF (red light) that freaks them before the flash freaks them. Doesn't look like over 100 bluegills in a 300 gallon tank but it is.

Thanks - looks like 40-50 fish - nice size.

Apparently the rest are inside the front edge of the tank and to the right. I know I counted about 104 and only lost two. One jumped up onto a shade net I had and couldn't get back in and the other was swimming erratically so I removed it. No fish on the floor!

This explains why I've bought fish and was sure I got less than they said!

Can you explain your setup in more detail, I am trying to figure out what you have in the center of the tank as well as what the pipes are in the picture.

Thanks

MrHello,

Basically there is a hole cut out in the center of the fish tank (4 inch hole for 3 inch Uniseal) The Uniseal takes the place of a more expensive bulkhead fitting.



A piece of 3 inch PVC with a shower drain inserted and glued into a section of 3 inch PVC pipe and a plastic washer to keep it from pulling through the Uniseal and tank, goes down from the center to an elbow via a rubber coupling.

Here's is the shower drain without the grading cut out.



Here the grading has been cut out:



Here are the three components separated:



On top of the shower drain in the center of the tank is a flat plastic plate attached with stainless steel screws to keep the fish in (1/2 inch gap), but also allow water to flow down to the clarifer tank (plastic drum).



Here's a membrane diffuser attached to the flat plate, which btw, also prevents a vortex from forming as the water goes dowh the drain, which is advantageous. The diffuser added oxygen and is supposed to help in self cleaning of the tank.



Here's a view under the tank to show the connections.







From there the 3 inch PVC drain pipe goes along the floor to a gate valve and another rubber coupling. When draining the clarifier tank to get rid of solids I close the gate valve and cap the siphon tube to prevent draining the tank. (This is the yellow perch tank).



Another short piece of PVC connects to a 't' which connects to a plastic drum on the vertical part of the 't', and the rear edge of the 't' goes to a drain hose and ball valve to close or open the hose.





Water is pulled up through filter material in the barrel to both the spray bar and the RBC tank via a small pump sitting on top of the filter material in the barrel, which is adjusted with a ball valve. The overflow goes back to the fish tank. The water going to the RBC tank drops in center paddles which turn the RBC.

That's just too cool.

I just got an email back from the author. Steve says it's sold out but he is going to have more printed. Whoever buys that book at $2400.00 or $900.00 and then it comes back out for $25.00 is going to be pissed!

Here is one on ebay that did not sell. See the ad "Compare elsewhere at 900.00" SCA ebay

Uh-Oh JKB....looks like the bottom may be about to drop out of the aquaculture reference material market!

Here's a pic of the YOY yellow perch in the perch tank. Again there doesn't seem to be as many fish in there as it looks but there are about half of the 728 fish in there with the other half at the high school.



BTW that's not algae in the tank. It's a combination of iron (in make up water from well) and tannins from the feed. Looks more a light brown than in the photo.

The fish are feeding so well 3 X per day I'm doing slightly over a 10 percent water change per day. Some pretty wicked smelling solids come out of the bottom drain and clarifer tank! A quick pull of the gate valve and a ball valve on open and most of it goes down the drain! What doesn't go down is sprayed down with a garden hose and nozzle.

Gotta go. It's feeding time again.

Cecil,

We are about to finish our house and I am getting ready to set up my system in the basement so it is ready for the fall. I am looking a possibly a square 180 gallon tank because it will fit better in my space. Do you see any problems with a square tank vs. a round one?

It won't self clean very well and you'll have solids sitting on the bottom in what are known as "dead zones." You can do it but you will be limiting your carrying capacity by not removing waste efficiently.

In my first tank that was circular but did not have a center drain or centripetal flow I was constantly netting up solids on the bottom. Of course every time I did this I stressed the fish.

Couldn't you block off the corners somehow and help improve that situation?

Square and rectangular tanks require some engineering to make functional. That said, they are far more self cleaning than a round tank could ever be.

I would go with round or oval for starters and keep it simple.

Square is more self cleaning? Then why would I go with round? The tank I am looking at sits in a rack and has a low spot in the middle of the base (not a cone, but not flat in the bottom).

Square tanks need to be custom built for them to be self cleaning.

I am sure the tank you have will work to an extent.
Maybe have to spend a little extra time cleaning and such.

How many fish are you planning on?

Can you show us a picture?

Cecil, what size pump (GPH) are you using?

Here is the picture from the Harrietta Hills catalog.



It is 180 gallons. I could not find it on their online catalog. I know that round would be ideal, but 42" x 42" will fit into my space so much better. The round is around 60" in diameter. If anyone knows of a deeper tank that would be roundish and around 200 gallons, please let me know. I can work with under 50" in my space. Rubbermaid has a 150 gallon oval that might work.

I want to raise around 100 tilapia over the winter. I have two fish tanks for the brood stock and raising the small fry. This trough will be for the fish up to about 6 inches.

I couldn't disagree more JKB and so does Dr. Timmons, Dr. Ebeling, or Dr. Summerfelt, three of the biggest names in RAS' but hey we don't always agree do we JKB?

The engineering I've seen to effectively keep clean rectangular and raceways systems with all the plumbing is beyond most people that are starting out.

Yeah what you said in bold! Another stressor for the fish!

Coach,

Stay away from rectangular and oval tanks if you can for you first project. Sure you can make them work but it's a lot of extra work and not very cost effective for what you want to do. On the other hand if you must, you can probably get away with it as tilapia can handle dirty water, ammonia, and nitrites better than other species. Maybe it's just me but when I build something I want it as cost efficient and working efficient as possible.

I have a round tank that is 48 inches in diameter that is cut down from a water storage tank. If you can find a plastic tank manufacturer in your area they may have some sitting around they'd be happy to cut down for you. That's what this one did for me:

http://www.assmann-usa.com/Open_Top_Tanks.htm

They told me whatever size I need they will accommodate me if I give them a heads up. Of course it helps I ran cross country and track with the salesman's dad and really talked him up.

The one I got from them, any feces rarely sits on the bottom very long due to the smooth surface, and the spray bar I installed creates a circular flow that sends it down the drain pronto.


I got it for much less than any of the commercial tanks.

Rural King also sells a 4 foot plastic stock tank very reasonably. I can get one from my local store and not pay shipping if I wait for them to get it in.

Whatever you do don't pay shipping for a tank! It can be more than the cost of a tank! It's ridiculous!

It's 600 gph and 35 watts. I got it from Stoney Creek.

You can run an entire system on air even more efficiently.

Yes but why not just get a circular tank and not have to make alterations?

So you have a better mouse trap on paper? Please don't take offense, but something on paper that has not been evaluated is not as significant as someone that used all of the above, and documented their trials in research studies and books using several species. The three gentlemen I mentioned that have shown circular tanks to be superior for a lot of reasons.

I've met Summerfelt and if he's anything he's a very gifted engineer. When he starts in with is graphs, stats, and field trials you can get lost if you're not paying full attention.




Have you actually raised any fish in an RAS yet JKB? I'm impressed by your ideas but engineering is only part of the equation when it comes to fish as there is a biological component.




I don't know you well. Don't even know your real name although I'm thinking it's Phil? I would hope you don't but many have. The last 20 years are replete with systems that looked good on paper but failed to be economically feasible due to too many bells and whistles.




That's nice but sometimes the more gadgets you have the more can go wrong. There's nothing like a person that is constantly watching vs. depending on gadgets.

Seems like the wrong species to get data from for your interest in raising coldwater fish like coho.





Not exactly. I said they don't have a bottom line to worry about and have plenty of funding so their systems as portrayed may not be duplicatible for everyone. But they still can show technically with data what does and does not work. I.e. tanks that are not self cleaning are doomed to be inefficient and reduce profits by elevating ammonia and nitrites levels.



Yes we do.



Likewise. I go by personal experience and as president of our aquaculture association I get to see what works and what doesn't work when it comes to the real world.

I'm looking forward to you sharing your system in photos here like I did - if you do.

I'll just refrain from posting on this subject in the future

Now JKB. You refute what I said completely and you expect me to not say anything?

I'm done on this thread. I won't convince you and you won't convince me. No need to get anyone's hackle's up.

I still look forward to your threads and look forward to the time you get your system running.