Small scale recirculating system pics

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 an individual named Ken Grymala's post on the Pond Boss forum, I found the idea to built a neat portable spray bar for it that is powered by a 12 volt battery with the use of a small bilge pump.



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 to seine out the fish, 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). A 3 inch slip PVC shower drain with the mesh pattern cut out is part of the drain. The lip was not big enough to prevent from pushing on through so I made a washer out of plastic wall covering. 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.

Edited by az9, 30 December 2011 - 12:57 PM.

More pics:

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 ideally strains out suspended solids from the tank. Or at least this is the idea. 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 spray bar has holes drilled in every 2 inches. 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.

Edited by az9, 30 December 2011 - 12:58 PM.

Fantastic set up. I've been eager to see more pictures of it since seeing those you posted a couple months ago. Am I right in understanding that there are 300 yellow perch and 100 bluegill in separate tanks simultaneously sharing 1 RBC? How long does it take for it to cycle at that load? Just out of curiosity, How much extra growth do you estimate the fish put on while inside for the winter? Those bluegill are looking nice and plump in the last picture of them.

Very interesting, thanks for sharing.

Steve.

Edited by frogwhacker, 31 December 2011 - 07:41 AM.

Fantastic set up. I've been eager to see more pictures of it since seeing those you posted a couple months ago. Am I right in understanding that there are 300 yellow perch and 100 bluegill in separate tanks simultaneously sharing 1 RBC?

Yes.

How long does it take for it to cycle at that load?

Not sure what you mean. Are you talking about turn over? If so, there are two pumps that pump a total of about 1200 gph when head is taken into account. The the volume of the entire system is about 700 + gallons.

Just out of curiosity, How much extra growth do you estimate the fish put on while inside for the winter? Those bluegill are looking nice and plump in the last picture of them.

I'm anticipating about about an inch a month with the yellow perch and a little less with the larger bluegills due to their advanced size.

Very interesting, thanks for sharing.
Steve.

You're welcome.

Not sure what you mean. Are you talking about turn over? If so, there are two pumps that pump a total of about 1200 gph when head is taken into account. The the volume of the entire system is about 700 + gallons.

I was wondering about the bacteria in the RBC. Do you keep the bacteria fed while your not using it, or do you let it cycle once you've added the fish? I guess that would probably depend on how long you were going to have it down though? I was wondering how long it takes to build up enough bacteria to deal with that bioload, but then after thinking about it, I guess it probably wouldn't take any longer than a filter in one of my aquariums......more fish, but also more surface area for bacteria. Thanks.

Steve.

P.S. The largest thing I deal with is 150 gallons, and that's just got one fish in it. The amount of water and the pounds of fish this system supports just amazes me. Thanks again.

I was wondering about the bacteria in the RBC. Do you keep the bacteria fed while your not using it, or do you let it cycle once you've added the fish? I guess that would probably depend on how long you were going to have it down though? I was wondering how long it takes to build up enough bacteria to deal with that bioload, but then after thinking about it, I guess it probably wouldn't take any longer than a filter in one of my aquariums......more fish, but also more surface area for bacteria. Thanks.
Steve.

Steve,


Last year I let the RBC just sit dead in the water not even turning. That was a mistake. I was told by a very experienced PHD down the road that raises hybrid striped bass, that I would have to clean the tank and RBC and sterilize to start over. He said he had nothing but problems with heterotrophic bateria when he shut his system down and tried to start it cold turkey so to speak.

I will either keep the RBC running (but drain the water from fish tanks) and feed it with ammonium chloride or non sudsing ammonia when there are no fish, or I will either keep raising fish at the same rate or keep a few fish in the tanks to keep the filter fed. Not sure yet.

P.S. The largest thing I deal with is 150 gallons, and that's just got one fish in it. The amount of water and the pounds of fish this system supports just amazes me. Thanks again.

It can go much higher but I'm not willing to make water changes every single day nor do I have to push my system so hard as my fish are high value and my capital costs are low.

Edited by az9, 01 January 2012 - 11:00 AM.

Can you add some plants in there to soak up the excess nitrates, think aquaponics, to avoid excessive water changes? Something as simple water cress or lettuces would take up all that excess nutrient. Can't let that nutrient rich water go to waste:)

Steve,


Last year I let the RBC just sit dead in the water not even turning. That was a mistake. I was told by a very experienced PHD down the road that raises hybrid striped bass, that I would have to clean the tank and RBC and sterilize to start over. He said he had nothing but problems with heterotrophic bateria when he shut his system down and tried to start it cold turkey so to speak.

I will either keep the RBC running (but drain the water from fish tanks) and feed it with ammonium chloride or non sudsing ammonia when there are no fish, or I will either keep raising fish at the same rate or keep a few fish in the tanks to keep the filter fed. Not sure yet.




It can go much higher but I'm not willing to make water changes every single day nor do I have to push my system so hard as my fish are high value and my capital costs are low.

Can you add some plants in there to soak up the excess nitrates, think aquaponics, to avoid excessive water changes? Something as simple water cress or lettuces would take up all that excess nutrient. Can't let that nutrient rich water go to waste:)

I'd like to but I'd have to stop adding NaCl and wait for it to dwindle down to nothing after the water changes. I'm leery of eliminating the salt as it's a very cheap insurance policy. But I do want to do some aquaponics at some point and eliminate nitrates at the same time.

Actually, I'm less concerned about nitrates than I am about dissolved solids and DOC's. I plan on building a small foam fractionator (protein skimmer) very soon to see if I can produce some foam to further clarify the water. Contrary to popular believe they are not just for saltwater as is evident in this Koi Pond.

Edited by az9, 02 January 2012 - 05:45 PM.

Here's another picture. It's 300 plus hundred yellow perch YOY (Yeah I know it doesn't look like that many) in my secondary smaller HDPE tank. These things are eating machines snarfing up commercial feed 3 X per day. I flush out a lot of waste when I do a water change! Color is due to tannins in the feed and/or some iron from the well make up water.

Nice setup. I'd like to hear more about your niche markets.

A friend of mine once had a similar system but with plant beds replacing the RBC: http://www.townsqr.c...saqua/page2.htm

What reminded me was your center drain and spray bar arrangement. He used a similar design but had conical bottom tanks and a single return spray head made from a 2"pvc cap with holes drilled. The combination of centrifugal flow and conical bottom carried all solids to the drain. I don't recall the flow rate but it didn't seem all that high, just enough to create a steady flow. He raised tilapia.

Your diffusor located above the drain also helps direct solids to the center, as I'm sure you planned. I do the same in my system with airstones suspended above each pump.

The salt in your system would limit crop choices with a plant component, although there probably are some salt tolerant species that would work. You might also find that the synergy provided by a plant component would reduce fish stress and eliminate the need for salt. Plant beds take up more space than an RBC but it's balanced by the added benefit of another product to sell/eat. I placed my fish vat beneath the walkway to save space. There also are simple raft designs where plants float on the water surface on styrofoam rafts with roots submersed. Adding plants might make an interesting student project.

How do you maintain 75 degree water temps? Is that ambient air temp? When i raised tilapia I maintained 85 degree water temps but found it economically unfeasible (especially when tilapia prices tanked with imports) and switched to hybrid bluegills. My temps range from 60-70.

Thanks for the reply LB. I haven't been back here for a short while or I would have responded earlier.

I had two niche markets: One is no longer, as the customer said their large pike and musky were eating the 13 to 15 inch yellow perch I was selling them. (Bass Pro Shops) I'm skeptical it suddenly became a problem. Probably cutting costs or they found someone cheaper. I have to deal with health testing for VHS for out of state sales because I'm located in one of the Great Lakes states, which makes my overhead higher. I also don't want to undercut my other niche market.

My other niche market is growing out trophy size feed trained brook and brown trout, yellow perch, and bluegill in my four ponds that I sell frozen to taxidermists. It's a lucrative market as public caught fish cannot be sold in most states. Taxidermists use them for show rooms, state, national, and world competitions, and for making replica blanks. I've also sold a few fish to people that specialize in making replicas.

I was considering holding, supplying, and delivering tilapia and grass carp this year for algae and macrophyte control for recreational ponds, but I don't think I will, as I already have too many irons in the fire and would rather use the capital for something else.

As far as the conical bottom being more effective for moving solids to the drain, according to text by two experts on RAS, Dr. Timmons and Dr. Ebeling in their book Recirculating Aquaculture that is a misnomer. According to them the centripetal force will move solids to the drain regardless of whether there is a conical bottom or not.

I plan on doing Aquaponics this spring outside once air temps get warm enough. I will not use salt in that case. Will probably raise tilapia for the table along with whatever my choices are for plants. I didn't do so indoors because I wasn't thrilled with purchasing lighting and the power consumption that would take. I also would have to partican off the lighting and plants and the perch and bluegill do not like intense light.

There is also a raised garden out side adjacent to where I plant to erect the raft tanks. I will irrigate the garden plants with my flushed solids water and of course circulate the fish water through the raft culture tank(s) and back to the fish. I'm probably going to use makeup water that I collect off of the roof of the house. It's a little more involved obviously with a biofilter and sump tank, and probably an UV bulb for eliminating suspended algae but I've already blabbered enough in this thread.

Edited by az9, 10 March 2012 - 10:17 PM.