flood and drain hydro with aquaponics

[mikeandy]

I was looking at putting together an aquaponics system this spring. I was thinking of doing an ebb and gro type of system with the fish tank as the source for food for the plants. What is a good rule of thumb for size of growing beds for plants, per the number of fish? gallons of water?


thanks
mikeandy

[keith_r]

sounds like you mean what ap'ers refer to as flood and drain

general rules of thumb..

1 gallon of fishtank water to 1 gallon of growbed media (2 gallons media is better)

for every 100 gallons of growbed media you can raise 25lbs (grown out size) of fish - the media is your filtration and this is a guideline only, best bet is to start a little lower than that, i've seen people go with a higher growbed to fishtank (edited) ratio for denser fish stocking, by adding a sump to pump the water from so that the water in the fishtank stays at a constant depth

your plants would be limited by space and growbed design (some plants like deep roots)

it's a good idea to add additional aeration as well - some fish like trout would pretty much require additional air

[jackalope]

Yep! I would go with the 1:2 ratio - 1gal. FT to 2gal. GB That's the ratio I use!

As far as how many fish, the previous post will give you a pretty good rule of thumb, although I use a 1:3 ratio .....

as far as how many plants - if you test your drain from the GB for nitrates, it would seem that if it's neutral, you have it either just right or too many plants. If your plants start looking a little sickly, that would be an indication that there are too many plants and they are being starved for nitrates (ferts). I have read that you can add liquid ferts (fish oil, etc., NOT chemical ferts or hydroponic ferts) to compensate for overplanting, but I'd be very careful about adding anything to the water that the fish are living in! I have no experience in adding ferts to the water, I'd rather pull up some plants and plant them in dirt and then use the organic ferts to provide them with the necessary nitrates if I felt that I was overplanting! Just my 2 centavos ......

[keith_r]

good point on the adding fertilizers.. the only thing i've added to my system is "maxicrop with iron" (NFI) - a seaweed extract with chelated iron added

there are some natural things folks have added, like burying banana's or banana peels to add potassium..i would only do that if i had worms in my growbeds... i would recommend adding worms to the growbeds, either flood and train or constantly flooded... they'll help with mineralization of solids.. i had a few worms living in the bottom of my fishtank the first few weeks it was up and running (they got flushed out of the gb) but they were gone in short order after i added the bluegill..
i would say i put two dozen in each growbed (1/2 of a 55gal blue barrel).. when i moved one pair of beds indoors for the winter, i found quite a few worms looking fat and happy, and some little ones

some people have trouble with ph, but patience is best, it will come down as your system matures

[badflash]

I would avoid adding any sort of composting item to a growbed. If you need a mineral, find a food the fish will eat that has it.

[mikeandy]

I live in central North Carolina, where the winters aren't too harsh. This year we are having an unusually cold winter. when would be the earliest i could start to put everything together? Tanks, growing beds etc?

[urbanfarmer]

The quickest and cheapest fix for needing some liquid fertilizer is to pee in it, and it doesn't get more organic than that for the price. I would suggest doing this in the grow bed or any area that is just after the fish tanks in the water flow cycle. That way by the time it diffuses into the rest of the water it has fully diluted and perhaps much of it has been broken down into nitrate.

If you have any liver or kidney disease and you plan to share your crop, do not do this because there could be blood in your urine or pathogens. If you are on any medications, you may want to research what the medicines metabolize to, to ensure it won't harm your plants, fish or you. Normally, urine is perfectly sterile when fresh.

Good luck and take lots of pictures... wait no not this time.

[stucco]

I’ve read that leaving it in a sealed jar for a couple days helps with pathogens and whatnot.

[badflash]

I live in central North Carolina, where the winters aren't too harsh. This year we are having an unusually cold winter. when would be the earliest i could start to put everything together? Tanks, growing beds etc?

That totally depends on your choice of fish and plants. Giant Hybrid Sunfish can handle cold and most greens, peas, spinach and cole family plants do fine as long as it doesn't freeze.

[keith_r]

yup, you can start any time...
it will take longer to cycle up the system if it's real cold, but, if you just pump during the day when you first get it up and running, (and your ft doesn't freeze overnight) you could be cycling within a couple of weeks i would think

go with fish you can find locally and they will handle the temps better..

if you are not on any meds, using your pee is one of the easiest ways to do it, but be forwarned, there will be no amonia when fresh!if you pee directly in your tank, you won't show am for at least a few days.. your best bet is to store it for approximately 2 weeks (the pee that is).. another forum member here did some pretty extensive testing with "pee-ponics" - that would be TCLynx