for your skimmer issue what type do you have? but what I and some others I know have done is just extend the plumbing for the pump and intake. IE:the pump is inside the tank and you just add a little extra hose or pipe to make it sit lower into the sump. its just a thought and keeps your DT...
Yeah I almost ordered from them when I first got into the hobby years ago. I just did a google search for reviews and I agree with the aquaCON part. Divers place is a good one though
Just follow the direction have new carbon ready and do at least 25% water change If not more and you'll be fine and as soon as u see more show up do It again. But make sure to siphon out as much as possible before treatment cause there's at least double hiding in the rocks and sand.