View Full Version : Do I Need Two Overflow Drains On A 110g?

12/23/2006, 09:14 AM
i built a 110g tank, see pic below..my question is should i drill two 1.5" drain holes instead of one? im working with close to 1000 gph return pump after head loss and a 55g sump.


12/23/2006, 09:47 AM
I have 3 on a 390, so you have more flow capacity per gallon than I do, so I think one should be ok. My return pump is a Dart, which is about 3 times what you want, so once again, I think its ok. Any particular you didn't continue the bracing all the way around???

12/23/2006, 10:11 AM
I would have a backup drain with that much gph running through. Unless your single overflow drain is HUGE, you'll probably be running it close to max. A snail or something clogging it even partially might cause the tank to start overflowing. IMO, a backup drain is a must. Most people just use their return hole as a backup drain on RR tanks.

12/23/2006, 10:21 AM
I would definately put 2 drains. You'll get a much better surface skim and wont have to worry about flow. Are you drilling 1.5'' holes which would accomodate a 1'' bulkhead? or are you installing 1.5'' bulkheads? If the latter, 1 drain should be more than enough.

12/23/2006, 11:08 AM
installing 1.5" bulkheads