Backyard Aquaponics
A place to discuss aquaponics

seeing the calcium build-up my bet its water related
you cant fill the system with different water

Well by the day after my post, I was down to a single 3" koi.
That weekend I had planned to drain the system & remove the plywood & metal a hurricane blew through. I still have not made any changes as I intended.
Now two weeks later however, that one koi is still alive and well by himself.
So it took 2 weeks for the water to kill 11 fish and I have one remaining @ 28 days.
To me, this just adds to the mystery. Seems like either this one remaining fish is immune to something in the water that killed the rest of the fish, or the deaths of the others freed up enough oxygen in the water for this one...

I think you need to jump on google and find a lab that does drinking water testing.

Send a sample of your AP water in and get them to run it for everything.

We have labs here that run these tests for people who wish to drink their well water, I'm sure you'd have something similar over there.

It could be your well water is just unsuitable for the fish, or it could be that your well is contaminated...

this is the sort of thing that happened to me when i had large zinc contamination (running galv. water tanks as fish tanks cos noob at the time) - constant deaths over a few weeks, but then the few that survive that live forever.

now, i was also just looking at the lid pictures again, it may be bad perspective, but the lid looks like it touches the water? the SLO top goes into the lid and the rest of the lid sits on water? if so, this is bad, even with aeration.

if the lid is touching, there is a chance you are right about the oxygen being freed up as gas exchange is horrible if the top is covered completely. (cover touching the water)

RJ,

+1 on finding a test lab... I think TCLynx at one point was using a lab in Orange City, FL and maybe one from one of the Universities in Florida. Check around or ask your local county Ag Dept where you can get your water tested. I recall TCLynx mentioning $40 to get a very complete water test done somewhere... Ask TCLynx about the lab she uses and maybe you can get to the bottom of this.

It might also be worth getting a 2nd IBC and start making a 2nd Fish Tank. Perhaps there was (and still is) something very bad in your old IBC?

--
Sam