Aquaponic Gardening

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Hello all,


I'm a newbie, very new to everything.  The idea of aquaponic fascinated me after 6 months of intense research on urban farming.  My plan is to master this, so I can turn it into a business, since I'm tired of working as an attorney, and wants to become a farmer (everyone think I'm nuts, but I dont have any passion practicing real estate law anymore). So over a month now, I finally set up a 275 gallon IBC system to test out Aquaponic.  To my amazement it's not as easy as I thought it would be.


I got 12 channel catfishs and about 20 bluegills from going fishing for them. Filled my growbed with 100 liters of generic medium, similar to hydroton. A week later all the fishes died.  Then I just found out, after more research to get a testing kit at Petco to test out the pH level, temps, Nitrates, Nitrites and Ammonia.  Got that yesterday and performed the tests.  pH is at 7.6, temp is always around 76 degrees, nitrates and nitrites and ammonia are in good standing.  Also yesterday I put 20 gold fish in.  Today, after work I test out the water again, everything is still the same but pH rises to 8.0, and 5 of the gold fish died.  I figured probably the reason is because of the pH level is too high.  I really want my pH level to be between 6.5 and 7.  What can I do to accomplish that?  I got some pH Down and Up droplets but for my tank size, I dont think it's practical with the small bottle.  Is there a better way to decrease the pH level, meanwhile it does not harm my fish and my vegetables.


Your expertise is greatly appreciated.





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Really it would have been a breeze if you cycled the system before adding the fish. We all live and learn.

Hi Kou,

The water change is to save the fish as they are under some serious stress right now. Even if they get through this there will still be gill damage and it will also affect the health of the fish further down the line. Yes the water change will slow the cycling but only by a few days. At 78 degrees it took me 10 days but that's doing everything by the book and with a few added tricks. It normally takes around two weeks with temps like yours. Make certain the new water is dechlorinated.



Harold, since I dont have another tanks, by doing a water change will help saved the fishes right.


If after doing the half water changed, I put an aquarium heater in there to keep the temps up to about 78-80, I should be fine right?




Fishless cycling with plants typically takes how long?

Fishless cycling without plants typically takes how long?





So you are saying you have like 40 fish in a system with only 100 liters of media bed.  You need more media ASAP.


Still same advice, do a 50% water change (water with no chlorine or chloramine.)  Don't feed until both your ammonia and nitrite levels are below .5 ppm.  Cycle up with fish actually normally takes 4-6 weeks under good conditions (managing cycle up in 3 weeks is usually fishless with all the tricks and there is still usually a 3 week period of needing to monitor water quality closely and restrain feeding once fish are added.  


Once your ammonia and nitrite readings are down to .5 or lower

Then you will have to feed very minimally and watch the levels to know if you dare feed that day or not.  If you want to be able to feed these fish up, you need a lot more media bed.  40 fish is a lot to start with, I don't care if the fish tank is 300 gallons, you need enough filtration to support the fish and a 100 liter grow bed is only about enough for 6 tilapia to grow out in my book and only if you are an expert fish keeping.

Cycling with or without plants takes about the same time.

It is the fish that change things.

In Fishless cycling you can bring the ammonia up higher without worry about harming fish and let the process take it's course.  Fishless cycling in good conditions usually takes 3 weeks


Cycling with fish usually takes 6 weeks  (some people might manage in 4 weeks with tricks like getting mature media from an already cycled system but it still takes time for the bacteria colony to establish in the new system.  Under less favorable conditions cycling can take 8 weeks.)

Thanks...I guess everything I've done is wrong. I'll do a 50% water change tomorrow immediately right after work.


BTW, how do you know if your water is without chlorine or chloramine?  I lived in the city and my water are filtered through the city water systems.


TCl, try to make me understand this chemistry.  I'm not a big fan of science btw, almost flunt all science course. How can a fishless cycling be faster than fish cycling system? The fish produce the Ammonia right?

If you are on city water, you probably have some sort of water treatment to deal with.  To know which it is, you need to contact your water utility to find out what they use.

Chlorine can be outgassed by leaving it out in a bucket or barrel in the sun or aerating it somehow for a day or three.


Chloramine takes weeks to go away just by aerating so you will probably need some other way to deal with it.


A carbon filter can get rid of either of those treatments.  They make a hose end filter that can take care of it or something like most faucet filters will take care of it as would something like a britta filter.

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