bummed in hawaii (dead fish)

[hellbent]

Oh no! I have 7 dead tilapia! I am not sure what caused it. PH is still low at 7.6 and ammonia is still within safe range. I added some crushed egg shells into the gravel 5 days ago, but it hasn’t changed PH yet.


I only changed a few things recently. It could be any of these or all of them:


I removed 5 large feeder comets, I suspected that they were eating a lot of the food. I fed them koi pellets and fish flakes once a day around 5. sometimes I’d feed them a little bit in the mornig, but not usually.

Its been hot lately, termites have fallen into the fish tank. These cant be bad for the fish, can they?

I added a bucket with holes and some of the duckweed into the hydroponic/water tank weighted down with some red cinder I had just washed the day before, hoping that the fish water would make the duckweed grow faster. I removed it.

I used some copper hinges for the fish tank barrel, I meant to change it, it was starting to rust. I took it out, wiped it down and used zip ties to serve as hinges.

I had a steel clamp holding down the hose down onto the pump I had. There was no rust. I swapped it out with a better pump that fit the hose.

I changed a few gallons of water, I do not have a lot declorinated water standing by, but have more dechlorinating now.

I hope the remaining 5 fish make it, but don’t have high hopes. I have the dead fish on ice. They range from 4 inches to 2 inches. I will try to cut one open tomorrow and see what I can find, but I didn’t do that well in biology, back in high school 20 years ago.

[hellbent]

some more relevant information:

my barrelponic system was started about 2 weeks ago. for 3 or 4 days i had a 6 comets in the water tank, to start the ammonia cycle. i then added 12 tilapias and removed 2 comets. 1 comet was missing, i assume it jumped out before i installed a lid on the barrel.
i've got an old double whisper air pump going, a 300 gallon per hour pump pushing water to the grow bed filled with black cinder, going to another 1/2 barrel with nothing but water and the siphon. the syphon is a U-siphon that Glenn from Olomana Gardens invented. i havent timed it but it cycles a few times an hour.

[Dufflight]

Are you salting. 2ppt of sea salt.(1kg per 1000ltrs = 1ppt)

[hellbent]

no, what kind of salt do i use?

another 2 dead today... i cut them open, one had some really green fluid in its stomach. i didnt see any food it its stomach.

[hellbent]

im going to chalk it up to new system instability and try to find a local version of seasol.

[hellbent]

i am a dummy. the sea salt i was using, i saw on the front that it doesnt contain iodine. reading the back today 'contains anticaking agent' yellow prussiate of soda.
i think my tilapia's starting dying off before i added salt, but this cant have helped.

anyone know what this will do to fish? it cant be good, but the plants seem to be okay. anyone recommend a total water change?

im down to 14 feeder comets now.

[Outbackozzie]

Yup total water change. Sorry