PDA

View Full Version : newbie question on FT to GB ratios



oaktown doug
03-01-2014, 09:27 PM
Hi :
I have a preexisting 7x9x2.5 foot (approx. 1200 gallons) pond that I would like to use for aquaponics. The area that I intend to use for a GB is only 12x2x1 foot ( 180 gallons). This would make a completely backwards ratio of FT:GB of 5.5:1. Is this worth even trying? It currently has a 2000 GPH skimmer filter with a waterfall that has a diversion valve that could feed the GB or I could add an additional bottom pump. It currently has about a dozen 4" gold fish and 3, 10" koi. I was hoping to raise either hybrid striped bass or bluegill. I could add a separate FT if necessary but I am hoping to avoid this if possible
Thanks
Doug

Oliver
03-02-2014, 03:38 PM
Doug,

As a quick look, I see no reason why your plan will not work. There are limitations and those have to do with the size of your grow bed. I am assuming the grow bed(s) are media filled. If so, then you will be limited to about 30 pounds of fish. With the amount of water in your system, it will require a little time for the nitrates to build to a level where you can grow plants, but it will also stabilize your system. This will allow for a slow growth of the necessary bacteria for fish waste conversion. The system will take some time to cycle but you need not worry about getting ahead of it due to the low fish density.

I am not familiar with raising your choice of fish but be careful to limit your total weight to what the grow bed/biofiter can handle and be sure to aerate your pound. Please read Aquaponics 101 on this forum to get all the numbers.

Oliver

oaktown doug
03-03-2014, 12:07 AM
Thanks for the info! Do you think I can get away with diverting water from the top skimmer filter or would it be much better to have a separate pump from the bottom of the pond?

dead_sled
03-03-2014, 08:25 AM
I would estimate that you need about 350-400 gal/hr flow to the grow bed. This should allow it to cycle about 4 times per hour, assuming you use media (rocks, expanded clay, etc) in your grow bed. If you can spare that much flow from your filter, then give it a try. Personally, I think I would just get another pump, a bit oversized, and run the grow bed off of it.