Flow in a 105 g 30" deep wedge lps:

[Sk8r]

I'm setting up for a new tank, and want to arrange something simple that will keep the tank clean and flow brisk. I have a basement sump, Iwaki pump that I have to rein back: it can deliver all the push I need. My notion is to hard-pipe an inverted U from the 1" return pipe, with one side of the U as an open-ended pipe extending over the rim of the overflow and down about 3/4 of the distance to the bottom, and drill some fairly substantial holes in two rows down its sides. This pipe will be behind the rockwork, and will have 2 rows of drill-holes, each aiming toward the walls of the tank from the apex of the wedge-shape, so there will be bounce-back of current from the walls.

Any notions on this idea?

[tommyhrs]

FWIW You may want to test hole sizes and angles to achieve what your going for. Start small and increase a little til your happy with results. Also you may need to increase hole diameter as you get deeper into the tank to compensate for head pressure and water resistance. Another sugestion would be to vary the angles slightly to get more turbulent flow.

[Sk8r]

Thanks for the ideas!

[tommyhrs]

Another thing came to mind your rock structure could vary results a great deal... You may want to test with rock in place and adjust hole heights to get best flow thru.

[Sk8r]

True---if I do that pipe as removeable (who cares if it leaks under water?) I can make adjustments.

[tommyhrs]

It makes for easy break down and cleaning also. I doubt you'll get much leakage with an openended pipe... although i would put a screen on it. Some critters just don't know they're screwing up our designs. :D