Hi, first time posting, I have mutliple fish tanks, the one in question has been settled 3 years, however in past week I have lost multiple fish, all different species and sizes but mainly the older fish, they all seem to start swimming upside down asif their swim bladder has an issue, resting upside down, with the ability to still swim yet they just lue there upside down. They die about 2 days after they start swimming upside down. my feed, water changes are same for all tanks...one fish has literally just died in the time I wrote this, any ideas? Pic related
>>2028955
Test the waters.
>>2028955
something bad must have gotten dumped in the water.