Outdoor FGT problem

[featherfin]

Hey guys，

I've a 6ft By 3ft FGT partially exposed to the weather

Have cycled the water but somehow, after raining - all my fish turned belly up. Have been keeping goldfish, Koi and even Catfish - yes even the catfish died in there!

Have bought test kits to check on the water parameters and the reading looks fine.

Any recommendations on pond specialist that I can turn to - the last one made changes to my filter box but problem still persist.

Thanks

[noidea]

Rain water fall into your fgt from the roof or direct from the sky.

[Dave57]

recent mosquito control, fogging, insecticide spreading, etc...
rain water might not be so safe for fishes after all.
however, it is not conclusive for now.

can you share with us a description of your set up, as noidea asked, how did rain water get into your tank? direct from the sky, flowed through roof gutters, etc?

[millenium]

Could be many things. Like change water even a little need to add anti chlorine. Acid rain. Any algae boom? Upstairs or from outside got people sabo.

[featherfin]

Hey guys - the rainwater run off from my patio roofing before pouring down on to the ground. In the process, inevitably, some would flow into the FGT

[Aro77]

hi , what's the PH of your tank when u used the test kit?