Trout in tidal fishtank

[Lorenz Michels]

Hi,

I am currently building an aquaponics system. In my design I have 4 IBC's of 1000 liter (= 264 US gallon). Three of which will be a fish tank and one of them will be a sump tank. I plan to use rainbow trout. There are 9 ebb and flow growbeds involved, 4 of which are big and 5 are small.

That was my original plan. But now I consider to use all four tanks for fish tank. So there will be no sump tank. This means that the water level in the fish tanks can fluctuate. The maximal depth in the fish tanks will be approximately 900 mm (= 35''). In the worst case, when all 9 growbeds are fully filled with water, the water level will drop approximately 200 mm (=8"). I know that some fish don't like fluctuating water levels, but since rainbow trout naturally lives in fresh water streams, I can imagine that there the water level won't be constant as well and that therefore the rainbow trout won't bother my tidal fish tanks.

But he, I am only guessing. Does any of you have any ideas or suggestions on this?

Kind regards,

Lorenz

[Jim Fisk]

Well I feel you are creating way too many problems with that very pretty design. I started with the same thoughts but as I learned more about GH design and raising trout I came to realize #1 square is far easier all around, the best layout places the sump in the ground and my 5 IBC fish tanks should be at the highest point and GBs at knee to waist height. That way one pump sends the clear sump water to the FTs and all gravity from there thru the GBs and back ubderground to the sump. Simple proven design. Our has been running for 5 years and working great.

[Lorenz Michels]

Hi Jim,

Thanks for replying. Perhaps you know about Murray Hallams DVD "Aquaponics made easy". I think I will make a DVD "Aquaponics made difficult again" ;-). And I think I have to adopt a middle name beeing "Arch" because in most of my designs are arches and/or circles. Besides that, since I was about 8 years of age, I have been fascinated by Geodesic domes. About 3 year ago I was searching the internet for geodesic domes, when I stumbled upon a video of Rob Torcellini, who had build a dome and in it an aquaponics system. A what?! I thought, because I had never ever heard about aquaponics before. So I started reading, look at video's and started fantasizing about making my own dome and aquaponics system, because I was very enthousiastic about it. A year later it occupied my mind in a way that I had to start building.

Since my garden is only 10 x 10 meters (33 x 33 foot) and these square meters are partly occupied by a terrace, a path and some trees and because regulations force me to keep 1 m (3 foot) from the fence, I can't make a system like yours (which by the way is quite impressive). And because I wanted to have as much as possible growbeds, I came up with the 3 level plan. Fishies in the cellar and two levels of growbeds. And yes, this makes things difficult, but I love the challenge of it and the experimenting and the building. :-)

Since you are working with trout. Do you know the answer to my question in my original post?

Kind regards, Lorenz.

[Jim Fisk]

Hey Lorenz, as to the tide question It of course depends on just how much variation in tank volume we are talking about. Answer that and I can offer an opinion. However there are other things to consider like placing pumps in the fish tanks requires a great deal of filter clearing due to fish waste not to mention wear and tear on the impeller(s) due to solids handling. The sump in the ground eliminates all that allowing for a casual sump cleaning about once a year and pumps lasting for many years (on our second pump in 5 years). On top of that the fish tanks are always receiving fresh water from the sump and only requiring one pump rather than one in each fish tank. I went through all those scenarios in one month and broke ground satisfied that I had considered every option.

As to geo's I too considered one and drew many a plan over the one month I went from first hearing the term Aquaponics (Dec 15, 2011) and actually breaking ground with final design in hand (Jan 15, 2012). I had the blessing of having a brother in Austin that has been living with a 40' geo for about 10 years and his immediate answer was "don't do it. It is the most inefficient design on the planet" so I did not. If you consider the center height required for a decent footprint it is pretty obvious not to mention little things like fitting a shade cloth in Summer, etc. Yikes!. Just my experience on that. Here is just one of my many layouts using ibcs and barrels: (note the below grade sump in the center, 4 FTs around that and the rest of course GBs) Also remember that Trout require cool water and the FTs should not be in the hot house in my experience. I placed them in their own shaded N room for that reason.