"linear" overflow or "grooved" overflow?

[rdmpe]

I have read some info on linear overflows, basically an overflow that is just water pouring over a straight edged weir. I may end up replacing an existing overflow and getting some more holes drilled, and was wondering if I should try this linear overflow. I read that the water tends to sheet down the overflow making for a quieter system.

Anyone using a linear overflow and like it???

[roliva]

The purpose of a linear flow is to maximize surface skimming. The ideal length is the entire length of the tank but for most purposes, this would do:

The shorter the linear length, the thicker the 'waterfall' will be entering the drain, and you will start skimming not the surface but under the surface. This also causes a faster velocity of water creating a loud, rushing effect.

[roliva]

Oops, here's the link: http://reefcentral.com/calc/drain.php
and some more info:
http://reefkeeping.com/issues/2003-07/gt/index.htm

http://www.reefcentral.com/forums/showthread.php?s=&threadid=484537&highlight=linear+overflow