so egon you have been very help so far and i want to thank you for that. I was wondering tho with the bulkheads, so I can build more of a solid stand could i install the ones on the bottom with the threads inside the tank as long as i put the rubber gasket and nut on the inside as well. I figured i could also shorten the length of the threads so as to not disturb the fish. I'll be using pool filter sand as a sub-strait anyways. Any thoughts? oh and to the others that have been posting thank you for your help and encouragement. Please keep your posts coming.