Just did a large 15gallon change. Will double check copper levels after a work call here. I’m checking copper using Hanna checker. Only concern is getting the powder out of the foil packets. However, it’s the same setup as their phosphate. Tap the corners and make a “v” in the middle and pour carefully.
As for air toxins, if the fish are breathing them so are we.
As for air toxins, if the fish are breathing them so are we.