Hey I am planning on building a river tank for my Clown Loaches, and I have a couple of questions. First off, I plan on doing something like this http://www.loaches.com/articles/river-tank-manifold-design. This doesn't answer much of my questions though. I have a 135g tank that I have, and I was wondering what kind of current should I have in there, and what size of piping I should use for it. They use 3/4" pvc piping with two aquaclear 70 power heads, which will produce about 800gph. He suggests that I should turn it over 12 times my tank size which would mean i would need about 1600gph, but also I would probably need to increase my pipe size probably to 1". I wonder if this is correct. If any of you have advice I would greatly appreciate it.