Hello everyone. I've been stalking the threads for a while and I have novice question. What do you all do with your run off. I was under the impression it waste and no good to use so you toss it it right? But I've seen in other forums where it seems like it's being re used and ph tested. Just would like to know what's everyones run off routine in general. I've even read where others have said they shop vac it up.