Tank Design Help

[StirCrazy]

Originally Posted by Canadian

I don't know what part of sphelp's points you agree with Steve, but



sphelps is contending that a larger overflow would decrease the suction of the overflow and make it less efficient.

sorry, typed the wrong name LOL

[mark]

could easily build a Coast to Coast internal, and drain through the bottom of the tank (OF Tee shaped, think 2x4 on the flat sitting on a 4x4 post, or even the vertical box to one side, with your standpipe, assuming Herbie, in the 4x4 section).

RC has a calculator that gives weir length for flow. Not sure the reasoning but will give a water height of about 1/4" above the weir with the rated flow.

[superduperwesman]

Generally the extreme of any case proves the point.

Canadian your right that you don't want a overflow that's too small. If I have a flow rate of 3000 gph and a 3" linear overflow I'll be sucking a lot of water from under the surface and potentially not getting a lot of surface skimming.

sphelps you're also right that you don't want and overflow that's too big. If I have a flow rate of 1 gph and a 10" linear overflow the surface of the tank will get build up like crazy.

To small or too big can be bad but like sphelps said I'd rather error on the side of being too small and sucking out water from below the surface then have one that's too big and have some nasty surface buildup.

It all depends on how much flow you have coming from the sump. Some people prefer power heads for the majority of flow so the sump return pump is pretty small in which case you wouldn't want a really big overflow.

[Parker]

Thanks for all the adivce and the lessons in fluid dynamics I think we have the design wrapped up.