Backyard Aquaponics
A place to discuss aquaponics

i have had my system running for about a month now.
i had started the system with dechlorinated water and a few plants, waited 3 days, added 6 feeder fish, waited 3 days, added 12 small tilapias.
they were doing well until 10 days later when they started dying.

i suspect either a brass hinge i used to secure the barrel hinge that had rusted, or a metal clamp that i had holding down a hose to a pump. i removed both of those things.
i also had alot of termites in the water at night. this probably didnt affect anything?
i figure its probably system instability and spiking, since everything was so new. i didnt have a test kit at that time.

after the last tilapia died a few days later, i changed the water and let it run for a few days.
i added liquified organic kelp, some sea salt, and let it run for a week. i also used a a little of this bottle of nitrifying bacteria i bought from home depot to try to give the system a kick start.
i then added 20 small feeder comets. things were going well for a few days and but have been slowly losing fish. i am down to 15.
was hoping to add some tilapias again, but looks like i will have to hold off.

any suggestions?


Date pH pH High Amonia Nitrites Nitrates
5/30/2009 7.6 7.8 0-0.25 0 5-10
---------water change---------------
6/14/2009 7.6 7.8+ 0 0 0+
6/15/2009 7.6 8 0-0.25 0 0-5 *lost 2 fish
6/16/2009 7.6 8 0.25 0 0-5
6/17/2009 7.6+ 8 0.25-0.5 0 0
6/18/2009 7.6+ 8-8.2 0.25-0.5 0 5 *lost 1 fish
-------water added (4 buckets)------------
6/19/2009 7.6+ 8-8.2 . 0.25-0.5 0 0-5 *lost 2 fish

oh, i also had tried to add 4 crayfish into a floater raft tank, they died in 2 days.

How bout a link to the system thread so we can refresh our minds about how the system is set up. Flood and drain, what kind of media? Timers, other aeration, etc?

The pH is kinda high but that is not abnormal for a system start up since many of us get our water from limestone aquifers. My well water has a pH of 8 but I still need shell grit in my systems to keep the pH from dropping out once the system is cycled.

So depending on what your media is and the containers are my first guess about the problem is the source water. Chlorine can be allowed to outgas from the water over several days but chloramine is more persistent and could be stopping your system from cycling properly.

I doubt that the metal bits are what killed your fish, it happened too quickly. It is good that you removed them though because they could cause you problems long term.

Are there other possible contamination sources to your system? Could the media have been coated in something bad before you got it? Like sprayed with chemicals, herbicide, pesticide etc? Might there have been any bad chemicals or materials in your containers you used for the system? Has there been any chemicals sprayed around the place lately that could have drifted or washed into your system with rain? Barring those contamination possibilities, I would normally suspect water quality problems but it looks like your test results have not spiked badly. Is it possible you are buying feeder fish that are already sick?

do you have any fish left in the system? If not, I will suggest you try cycling up the system fishlessly to make sure you get properly cycled. Then add some fish to see how they do.

A few things that can do fish in.
Really high temps from a tank in full sun.
Sudden changes in pH
Sudden changes in temperature
Lack of aeration (If fish are gulping air at the surface just before dawn, you definitely need more aeration.)
Over feeding or feeding spoiled food


I hope you can sort out what your problem is in good order to allow you to fix it and move on to enjoying your system.

sorry, heres a link: http://www.backyardaquaponics.com/forum/viewtopic.php?f=45&t=5653
i am using red and black cinder. i think you call it scoria.

i have found the culprit. the sea salt i was using contains an anti-caking agent. thank you for the suggestoins, i am going to do a full water change.

America seems to have a lot of High PH problems, why is that?
HellBent no need to do a low Ph test if your ph is that high, the low will always read the same as Ph is to high for that test