Backyard Aquaponics
A place to discuss aquaponics

I'm trying to find a simple system and found this one /www.townsqr.com/snsaqua/page2.htm, I'm not sure if it's continuous flow of flood and drain.They talk about the small tank with the isolated pump working intermittently, I assume you would need timers or float switches to accomplish this.I may call them but there info pack is a bit high at $250.00 to handle at the moment.

I would like to move up to say a 500 gal tank with 100sq. ft of beds if all goes well, but I don't know about clarifiers and flux capacitors just yet.

Hay there Brydon2 and welcome

I took a very very quick glance at that web address you posted. I think if you spend a little time reading here for free!!!! you could design your very own system a bit simpler and easier than that. Or if you want an offline info source, BYAP Sells a book and DVD.

For 500 gallons of fish tank, I would recommend between 500 and 1000 gallons of grow bed media or gravel but it really depends on how much fish you want to stock. In metric it is 3 kg of fish to 100 liters of grow bed media. I think we figured that was like 6 lb of fish per 25 gallons of grow bed media.

You can do a system where you only need one pump. Look up CHIFT PIST (constant height in fish tank, Pump in sump tank.) Benefits are fish tank water level stays relatively constant and the pump is in relatively clean water which makes maintenance easier. Drawback is you need a fairly large sump tank (I usually recommend about 50-60% of the total grow bed volume for the sump tank to allow a bit of extra depth for pump operation and automatic float valve top up.)

Welcome to the addiction

TC, seems as if you're saying a 1:1 ratio, I thought the tank was always bigger.For instance, I am setting up a 29 gallon fish tank and just bought a 15 gallon bed container for starters, I thought it was small but should I use 2 to create a 1:1 ratio?

I've based all my calculations on the S&S formula where they use 3- 8'x4'x12" beds for each 500 gallon tank, The 500 gallon tanks I'm looking at are 8' circular by 24" high, thats 128 sq ft i think, the 3-4'x8'x12" bins should equal 96 sq ft so thats close to 1:1 I believe.I'll have to research the CIFT-???? type of arrangement you speak of.I will look at your system in the members area. Thanks so much for the help !!

The ratios are volumetric Brydon... not surface area...

In the Imperial system, the depth works out to 1 foot, so square feet = cubic feet.

OK...

O.K., Let me start with my small 29 gallon starter tank, The question is with fairly heavy stocking of 1/2-3/4 LB per gallon I can support one 60 gallon bed container.Sounds about right, right? Thanks!

The worst possible thing you could do... is overstock a small tank... IMO...

There's just no margin for error.... ammonia, DO, pH and water temp.... can just move sooo quickly...

Stock to the volume of your tank... and a minimum equal capacity of growbed volume...

Yep, I would use two bins with the fish tank and add another tank to use as a sump tank.

The ratio thing can get confusing. The ratio is grow bed volume to fish tank volume and around here most of us push for somewhere between 1:1 or 2:1. 2:1 would be like 200 gallons of grow bed to 100 gallons of fish tank. Now you will say how do you flood 200 gallons of grow bed with only 100 gallons of fish tank and still have any water for the poor fish. The answer is to add a sump tank. Don't figure the sump tank into the ratio formula since it is only there to buffer the water level fluctuations and add stability to the system.

Anyway, back to your small system you are working on... 29 gallons is a pretty small tank so don't push the stocking too hard unless you have a lot of experience keeping fish and keeping them alive under less than perfect conditions since as Rupe says, there will be little margin for error in a small system like that and things can go bad very fast.
With a 29 gallon aquarium, I would want at least 30 gallons of grow bed and then I would probably add some sump container into the system that is at least as big as the aquarium if not bigger.
Here is an example


or if you wish more than one grow bed container.


Just to give you an idea. I have a 10 gallon aquarium with 5 little catfish fingerlings. It is hooked to 5-five gallon buckets filled with gravel and they drain into a 55 gallon drum as a sump. Sure it is overkill but all that extra water volume allows that system to stay stable in nutrients, pH and temperature. And if I want to hook the larger aquarium back up to that system, I can.

TC, Excellent explanation!, I am beginning to understand the CHIFT PIST system.Now if 60 gallons of water does not overheat during summer this may work.

Question: When starting the system would you fill the GB or just the tank and sump?

Both.... if you're running Chift Pist... your pump (by definition) is in the sump tank...'

So to trigger the flow from the fish tank to the growbed(s) you need to begin pumping from your sump tank.... so that the overflow begins from the fish tank to the growbed(s)...

Clarification... both... as in fish tank and sump tank.... the growbeds and everything else will follow

If one was to bury both sump and FT with beds elevated would you need to pump from the FT?

Fill fish tank and sump tank with water. Fill grow beds with media (like pea gravel or clay balls but avoid limestone or marble chips). When you start the pump running the fish tank overflows to flood the grow beds (the sump level going down at this point.) Hopefully you still have a bit of water in the sump when the grow beds are completely flooded.

You then need to decide if you will manage your flood and drain using auto-siphons or a timer on the pump. (actually you would probably decide this before you fill your beds with media since it will affect what kind of plumbing you put in a bit.) This decision is affected by size of pump as well as the availability of an appropriate timer and if you wish the constant sound of running water or intermittent. If the pump is big enough to pump the volume of your fish tank several times an hour at the amount of head you are expecting of it, then it is big enough to use a timer. A handy rule is you want to move at least the volume of your fish tank each hour. If you go with a timer, you probably should also have an air stone and air pump running for your fish for the time between pumping. With timer operation, you could put stand pipes in your grow beds with small holes near the bottom to allow a slow drain and the top of the stand pipe would be just below your intended high water level in the gravel and act as the overflow.
If you want to let the pump run all the time, you would then set up loop or bell siphons or some other auto draining device for the grow beds so they will automatically drain once they fill to the correct level.

And yes, if you Bury both tanks and have the beds above ground, then two pumps would be needed. Another option might be to bury the sump tank, place the grow beds on the ground and only sink the fish tank into the ground till the "overflow" level is a couple inches above the top of the grow beds. Then you can insulate around the fish tank and grow beds. The bigger you make the sump tank, the more stable the water temp will be. Some shade cloth over everything can help and complete shade over the fish tank and sump tank will help against algae.