If anyone has ever seen any post I've posted, which isn't many, but I've complained about plumbing. I hate doing :uzi: plumbing. I'd probably prefer hot pokers to the eyes but here I am, again, dealing with plumbing. I got a used 90g. Corner-flo marineland tank and stand that I need to deal with. The overflow has two holes. Traditionally one is for the return and one to the sump. BUT. I don't like that I don't have a real emergency drain. I was wondering what can/should I do to be able to change it? I've seen some videos on switching the dorsal to a Herbie but with one overflow box my brain can't seem to figure out the best method to do the return. HELP...