Is too much primafix bad?

[discusgirl]

I am wondering if too much Primafix (like the bottle falls in the water) harm the bacteria/bio in the tank? I can't find anywhere what the ill effects are, other than dead fish in my tank and clouded water, after 2 25% water changes in the last 2 days.

Any ideas if I should scrap my tank or try to salvage it? Any and all suggestions would be appreciated.

thanks!

[pcsb23]

It cannot do any good. 25% w/c are never enough, needed to be 90%+