Can't remove chemicals from tank.

[Fishmanperson]

Hello, I recently used algae fix in my tank stupidly cause I though it would remove the algae but instead if killed all my fish except for my 3 Angels. I did 70 percent water change but it didn't seem to do much because my angelfish look like they're about ready to die. They have blue spots on their eyes cause of poor water quality even after the huge water change. Should I do a 100 percent water change? Cause I really don't know what else I could do but I really don't want my angles to die.

 

[GlennO]

Yes I would. Another large change. As much as you can do without stressing them out by having to remove them. And put some activated carbon in your filter.

 

[A201]

Some commercial algaecides contain Copper Sulfate. Which can be quite deadly to fish and Inverts if overdosed.
If the copper sulfate is chelated, WC's are the only way to remove it. Activated carbon will quickly remove non chelated copper sulfate from the water column.