Backyard Aquaponics
A place to discuss aquaponics

Hello Everyone.

I'm looking for critiques in my system plan.

I have three 1000 gallon tanks in a row. I want to use two for fish and 1 for a sump. As this is more an educational and hobby system, I want to have as much diversity as possible. I want to raise Koi, Catfish, Talipia, and Asian Clams.

My plan which needs work:

Tank 1 - receives most grow bed run off so is the cleanest. Raise and breed Koi, clams, and breeding Talapia here. Sand bottom for clams and breeding.

Tank 2 - Plan on Talapia and Catfish here. Catfish would eat extra Talapia babies and not having a sandy bottom will discourage talapia breeding(?).

Tank 3 - Sump and filter tank. The sump captures rain water and acts as the buffer level for all the beds, so the two fish tanks stay full.

Questions: Should I allow rain water to flow freely into and overflow out of the sump tank displacing as much water each time it rains, or should I capture rain water into a 2nd container and only use top top off the system? My roof can easily capture 500 gallons in a storm, which are very common in West Virginia.

What type of filtering should I do inside my sump tank. For lack of room, I was going to use a submersion pump.

Thank you.


P.S. This is all inside a 1000 sq ft greenhouse.

Capture rain water in another tank with a airstone running to keep water sweet. Treat water to same PH as your main system. If you keep adding rain water every time it rains you will upset your system and most likely would have to let the system cycle again which could result in loss of fish if it is done several times

hmmm. Good point. Thank you ccBear.

Don't know much about sandy bottoms?? How do you indeed to remove solids from the FT with a sandy bottom? If using pump you will need to keep it up off the bottom so as not to suck up any sand and destroy impellers.
SLO will suck up sand.

Mmmmm, maybe you could use and air lift, that will remove solids and not sand???

Thank you Kitachooch,

In my first tank, I was hoping my low fish population and clams would take care of themselves. I was thinking, no one removes solids from a natural pond. I will only have a few koi and breeding pair of talapia in there so the stocking densities are really low. Won't the waste break down over time? Won't the clams shuffle and make use of the waste? Isn't the solid lifter mainly for high stocking rates? The first tank overflows to the 2nd, and the 2nd would be my high stocking rate with no sand on the bottom. The 2nd tank overflows to the sump.

I just built a swirl filter and bio filter out of two 60 gallon olive drums today. Since my sump is large and floor space limited, I put them in the sump tank. If any sand gets from tank 1 to tank 2, it should settle on my swirl filter. My pump will located in a filter bag in the corner of the sump .

Hi jwnova99, if you are overflowing then i imagine you will get a large buildup in 2nd tank, and again if overflowing then what are the flow filters for as your solids will be settled on the bottom. I would recommend at least an SLO in the 2nd tank.

Put a SLO from 2nd tank into 3rd sounds like a good idea. My tanks are 15 feet long, the inlet and outlet are on opposite sides. From tank 1 to 2, should I put the water in at the top, or toward the bottom? How does the solids on one side of the tank best migrate 15 feet to the other side?

If you are overflowing into 2nd tank then not going to be able to at bottom so no choice, you will have to sweep your tank regularly, at least weekly i would imagine.
The pick up point of an SLO can take many shapes/designs, see mine below, i designed it to suit the square bottom of an IBC, you could design one that sends to parallel pick up lines across the bottom, just need to be careful how many how big the holes are in the pick up line, if not enough and or too small then restrict water flow, but if too many too big then not enough suction to pick up solids. You could also add a second SLO if you calculate flows carefully.

Nice system you have setup. I like the idea of putting a horizontal pipe along the bottom to suck up waste. Getting the flow correct will be a challenge. Maybe a 2" pipe along the bottom with sixteen 1/2" holes would do. 16 .5" holes as the same volume as a 2" hole. Since I'm flowing 1000 gallons an hour all 16 holes should flow into the main pipe.

Looking at your system I have a question. It boggles me that the IBCs weigh so much or is my calculations off?

4' x 3' x 12" deep is 12 cu ft, It looks like you are using gravel which is 100 lbs per cu ft, so does each bed weigh 1200 lbs before the water is added? Not sure of the conversion but does your grow beds weigh 500+ Kg before water? I see people's beds on some small looking stands or a bed perched on top of a IBC sidewise and think that the weight is too much.

Thank you.

Thanks mate, just remember it is always easier to drill more than remove them lol. But also you want ability to move more water than planned just incase some holes suffer some blockages. Kids dropped a rag in my FT at some point and it settles over part of the pick up but didn't cause a problem as there were enough holes.

I think i used about 40 X 10mm holes.

Wouldn't be 100lb per cubic ft thats where you went wrong i think, maybe 50lb per cubic ft???. I estimate about 300-350kg inc water and gravel per bed but just guessing here.
A lot of people mounting above FT use Hydroton to cut back on weight. They also tend to make the beds a little shallower.

How deep would the sand need to be ? to deep with no flow through it will lead to all sorts of nasties building up,in the tank with sand,the pic of the slo imagine the bottom legs stretching the length of the tank,over the top of that something like corrugated plastic roofing sheet is placed,so you now have plastic sheet,resting on the legs for the slo,you could have a few of these to give the necessary support.Then you put your sand on top of this,when you draw water it will flow through the sand,cleaning it, then on to its next destination.The plastic sheet would require holes and maybe something like door screen to stop the sand getting through.
This is just an ideal,there are many things to consider with this.cleaning for one but nothing is impossible.

I'm not sure yet on the sand depth. I'm thinking 3 to 4 inches. The clams as I understand them will stir the sand A low Horizontal SLO pipe with lots of holes and a filter sock laying on top or under the sand as you suggest might be necessary.

I'm reading a lot of forums of fish tank owners. There is a lot of data and thought about maintaining a sand bed as a self maintaining Eco system. There are also certain fish, snails and clams they use to maintain the sand. If I use pool filter sand which is coarse and heavy, I can use wet vac to stir and clean the sand once in a while. This tank will have low stocking densities compared to my non sand bottom tank.

Are you intending on using media beds for filtration?

If you put the SLO under the sand or place a sock on it you are defeating its purpose, might as well just have an overflow.
You could run the SLO over the top of the sand but drill the holes up the side or on top of the horizontals to avoid picking up sand but maintain picking up some/most solids. If you have a flow/swirl filter after then this will trap any sand picked up. (ideal)
You don't want sand settling in pipes in any low points and or bends etc as this will block up/resist flow down the track. If it makes it to the GB's, not really a major but will slowly clog it also, especially around where the water enters the GB's.
Not sure about you but i don't look forward to cleaning out any GB's, so i will do everything to delay that job.