Yeah the valves mount flush to the back of the tank so that will be nice. I'm going to attach them to the ply on the back before I attach the ply, making little notches for the bolts. I don't want to make them go all the way through the tank, and it will be really easy to adjust or shut off the flow of water. These are way easier to open and close than any of the 3" and 4" ball valves I looked at, and they were only about $15 a piece versus $100+ for ball valves. I really cant wait for this to be finished and put my catfish in there. I think my major problem is I can't stand to do anything and not do it to the best of my ability. I have so many large catfish right now they are comming out of my ears and somehow mine always grow large faster than what others report. I just hope that I don't lose any due to their cramp housing before my tank is finished. I'm shooting for newyears as my new finish date! I should have some time on thanksgiving weekend to do some more work.