prime overdose?

[subman]

I looks like one or more of my kids have been pouring prime into subman jr's tank. Now his fish look terrible and his clowns died and the water is cloudy. I haven't had a chance to test the water but fear the results will be false do to the dead fish and all the prime in the tank. I'm changing water asap and adding carbon to clear it up.

Just wondering if it could be the prime that caused it or something else?