Dumbest mistake

[feelingfishy]

I would chalk this up to experience more than anything.
A mistake would have been over dosing by accident, or dosing the wrong thing by accident, etc..

Well said, thank you for correcting that.

I guess the dumbest thing was dumping a full 60 gallon drum of freshwater into the sump of a 330 gallon system.

Never walk away folks!