RAS pictures

[Cecil]

Here's some pics and my latest tweaking of the RAS featured in Small Scale Aquaculture by Steven Van Gorder. I still have some things to improve as I think the center drain is reducing the effectiveness of the u-tube siphon. I either need to increase the size of the pump or separate the drain from the clarifier tank and u-tube siphon. The plan is the center drain removes settleable solids and the u-tube siphon siphons of suspended solids. But I'm not seeing much suspended solids in the clarifer tank filter material, but when I open the bottom gate valve of the bottom drain, after draining the clarifer tank, there are a lot of solids that come up! It seems the center drain is working well, but the u-tube siphon not as well. That is, unless the inflow of the center drain is keeping the suspended solids that come down from the utube siphon low in the tank.

Edit: I reduced the filter material (bunched up netting) and in one of the tanks am now seeing more particulate being trapped in the filter material vs. not just in the bottom of the tank and center drain pipe. Perhaps I was using to much filter material? That said, this is the smaller of the two tanks with a faster turnover so that may be part of the equation too.

The fish seem healthy and feed well 3 X per day.


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 in the Spring. I bring them in 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 and idea from the Pond Boss site (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. The were placed into a floating cage in the largest pond until the RAS was ready. I usually wait until October to take them out of the pond, 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. I didn't have any water quality issues in the largest pond then went to.



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 slip shower drain and section of PVC slides through a Uniseal installed in the tank and connects to a coupler which connects to a drain assembly (See next picture).



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. A local rotomold factory cut a storage tank down for me and gave me a great deal on it.

[Cecil]

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 centripetal 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 strains out suspended solids from the tank. Two 30 watt mag drive pumps run the entire system minus the 40 watt linear air pump that provides air to two tanks and an air stone in the RBC tank. 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 clarifier tank. The ball value allows adjustment 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. I have since replaced the plastic tarp with two layers of the highest density shade cloth. I was concerned I was blocking too much air with the plastic tarp even though darkness is paramount to bacteria production.

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:

[Cecil]

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.

[Pugo]

At long last pictures, Looking good cecil.. I have never seen a RBC like that one. Good job!

[Cecil]

At long last pictures, Looking good cecil.. I have never seen a RBC like that one. Good job!

Thanks for the kind words Pugo.

Here's my secondary smaller HDPE tank with YOY yellow perch. They are eating machines and feed three times per day. Water color is due to tannins in the feed and probably some iron in the make up well water. Due to all the wastes they are producing I'm up to a 10 percent water change per day vs. every other day. You should see the waste that comes up when I pull the center drain gate valve all the way up!

[Joey]

Hi Cecil

Thanks for the photos, great looking RAS with an impressive backup system.

Cheers

Joey

[kellenw]

Great pics bud!

I have a tripp lite UPS backing up my system as well. Nice little units, but I have found that some pumps are not fans of them. I'm thinking it has to do with the sine wave technique, but who knows.

[GaryD]

Hi Cecil,

Your day-to-day experience of recirculating aquaculture is particularly useful to us because you are about the only person (that I know of) who is take harvest-size fish from a pond and putting them into a RAS.

Do you grow them out further.....or is it just that you can access them easier when it comes time to mount them?

Gary

[Cecil]

Great pics bud!

I have a tripp lite UPS backing up my system as well. Nice little units, but I have found that some pumps are not fans of them. I'm thinking it has to do with the sine wave technique, but who knows.

I've heard that is a possibility. What pumps specifically do you have that don't seem to be a fan of them? What do they do that shows you that? Less run time? What?

I've had my unit trip a couple of times due to power interruptions and all seems to work well. I'm using a couple of mag drive pumps from AES. The school has a couple of Easy Pro pumps from Stoney Creek that can be used for fountains etc.

[Cecil]

Hi Cecil,

Your day-to-day experience of recirculating aquaculture is particularly useful to us because you are about the only person (that I know of) who is take harvest-size fish from a pond and putting them into a RAS.

Do you grow them out further.....or is it just that you can access them easier when it comes time to mount them?

Gary

Gary,

Actually they are not harvest size.

Right now the RAS is used to bring in YOY fish (4 to 7 inch yellow perch and 6 to 7 inch bluegill -- although the bluegill may actually be 2 year olds) -- for the winter-- to get additional growth on them vs. none outside in the ponds. Then most if not all will go out to a pond(s) when the water warms back up in May or so. However I may keep at least some of them inside for the summer as an experiment, and as you say they are much easier to harvest in tanks vs. ponds. I do have a three seines though with one that is 160 feet long that can harvest all the ponds.