Why can a 1.5'' drain pipe drain more than 2x3/4''

[dolokhov]

I've read that a 1.5'' drain pipe for a sump application has more draining potential then 2 3/4'' drain pipes. Does anyone know why this is?

[Carl]

This is a yes and no answer.

Yes the double sized single drain will have less friction and will allow slightly more water volume than the tow 3/4" drains.
However you may get a better flow pattern with two, so it really comes down to one larger high volume drain or two smaller low volume drains, but a more "refined" flow pattern with less harsh high flow areas.

Put another way, if you are going to have large "monster fish" I would go with the 1.5" drain, but if you are going with an Angelfish, Tetra, Discus, Amazon River type tank I would go with Two 3/4" drains.

Carl

[dolokhov]

Good to know thanks Carl