Backyard Aquaponics
A place to discuss aquaponics

I'm thinking of starting small but somewhat ambitious. I haven't slept well the last few nights while trying to imagine how to pull this off well and on a low budget. Let me preface by saying I'm in the Chicago, IL USA suburbs, where we have fairly harsh winters (yesterday was 4*F and winter hasn't even started yet. As soon as spring breaks, I'm planning on building a PVC greenhouse to house my projects in, nothing too big, probably in the 12'x10' area. So with limited space and money, I'm going to attempt to get this going.

But I haven't actually seen a design of this sort. What I am thinking is sort of a hybrid of different designs I've seen. Will this work at all? Does it seem like it would be an efficient design? How could i improve them without going "overboard"? One thing I'm wondering is if one AutoSiphon off the bed is going to be enough. I'm thinking i might have a wide tube for the autosiphon and have it splash into a bucket with holes drilled in the bottom on the first float table in order to regulate the rate of flow to the tables as well as aerating the water some more.

Also, any suggestion on money-saving tips would be much appreciated.

So, without further hesitation, I bring you my plans:

I'm hoping to start with 2x200-gallon tanks, a 1/3hp, 28g/m@10', 4.1amp draw pump(need some tips on pumps... is that not what i need at all?), a decently deep and sturdy trough of some sort for the grow bed(probably pea gravel), and improvised float tables.

Here are the pics:

Oh BTW, I'm planning on starting and blooming it with feeder goldfish and then moving most likely to tilapia. Considering I'm PLANNING ON using 200-Gallon (750l) tanks, and a 6-month farming cycle, how many do you suppose I should put in there?

Hi bhsx, what crops are you after with all the float tables? I think Tilapia like warm water (80-90F), and I'm not sure how well they will work in Chicago. They can go a lot colder, but below 70F, you start having growing and mortality issues. Floats are often used with lettuce, but I'm not sure how lettuce will do with the temps you want for Tilapia.

I like a lot of what I've read on Tilapia, but they are definately warmer blooded than what you can do without a greenhouse. I also seem to recall that grow-out time for them is in the range of 8-9 months.
If you are planning on more year-round you can heat the tanks....

One more thing, do you have a large enough volume of Grow Bed? I don't know the ideal stocking levels, or how much the float tables will reduce that requirement.

Good luck, keep us posted.
-Doug

To make sure I understand: Water goes from Fish Tank 1 to Grow Bed, out autoSiphon, to Float Bed 1 to Float Bed 2 to Fish Tank 2 to Fish Tank 1?

If that is the case, I would be a little concerned that all the nutrient might be depleted by the time the water gets to Float Bed 2, but I would definitely like feekback from other folks on that. The other thought I have is that while the float beds increase your overall volume of water, they don't give extra filtration. You may need to re-balance your ratio of grow bed to tank to take into consideration the stocking ratio comments below. It does look kinda cool though, and it would be fun to compare float vs growbed. Overall, I give it a thumbs up!

I also use little plastic tubs with holes to aerate the water. I wish I had 2 fish tanks to be able to separate different sizes of fish...maybe someday. I'm not sure you need to be concerned about regulating flow to float beds so much. Remember that the media takes up at least 50% and maybe 80% of the space in the bed, so when the autosiphon dumps, it's less water than you might think. I currently have 100gal worth of grow beds, filling alternately--so 1 50gal bed at a time. I only dump about 17gals at a time (over about 10 minutes), so my fish tank doesn't vary that much.

Stocking Rates: Optimal ratios are based on the worse of filtration media or gallons of fish tank (I don't know how float beds count in the equation, maybe as fish tank.). A ratio of 4gal media to 2 gal fish tank water to 1 pound of fish is probably the highest stocking rate that an expert in AP would try. The real answer is that the proper stocking rate will vary based on your expertise with fish. Good Idea to start with goldfish (only a few!) and cycle up with those. I'm up to 4 goldfish in my 100gal setup. I think I will put in 2 more this weekend. Ammonia/Nitrites are holding at 0, Nitrate about 20.

I'm currently researching tilapia, after having been dissuaded from catfish and yellow perch. I just put a request in at my favorite aquarium store to see if they can get me proper beeding stock to try to do hybrid tilapias. YummY!

Rubbermaid stock tanks are nice, and reasonably priced at a local feed store. They are 2' high and oval in 150 and 300gal sizes. Their 50gal stock tanks are 1' high and make nice grow beds.

Yes, the tank is pumped upward to the grow bed, which empties through the autosiphon to the float beds which eventually dump back to the tanks. The separate tanks are intended to grow different species or house fingerlings. In the latter case i think the tanks would be divided differently.

Thanks again.

Greenedo,
I think you're correct about the growbeds... if i want to stick to 1:1.5 ratio, and assuming my calculations are correct, I'd need 75 cubic feet of grow bed for a 400-gallon setup. I've only planned for about 36 there lol...

I'll have to rethink those ratios and come-up with something a little smaller perhaps...
Or heck, I may just have to figure more growbeds into the equation

Tilapia does like it warm--I'm heating the water even though it's indoors. The hybrids will grow out fast. 6 months per harvest would be easy to achieve according to what I am reading.