something destroyed my whole tank, please help

[Delphinus]

I'd leave the skimmer on but have it overflow back into the tank, if possible. That's what I did anyhow. It was basically unable to skim properly anyhow, but I figure the air exchange is still good for something. Often times when there's a large die-off (like from the flukes from the medication - or even say a cyano treatment), there's a large drop in oxygen in the water. So the skimmer helps against that.

Good luck with everything!