View Full Version : Over flow

03-30-2005, 05:36 PM
How can I get my over flow to keep up with my pump. I have already tried two U-tubes that didn't work so I tried two much larger u-tubes. Still I can only run my Mak4 at around half flow. I have the extra running back into my sump so I don't put a load on my pump. I have only had my sump running for about two weeks I would like to have the full flow of my pump coming back into the tank for more water movement. :sad:

Any thoughts would be great :biggrin:


03-30-2005, 05:45 PM
What amount flow is your overflow rated to?

A Mak4 is rated at 1000 GPH at 5' of head. Im going to guess that your overflow won't be able to keep up with that. You might be able to add another overflow and get away with running a Mak4.

03-30-2005, 05:49 PM
What pipe diameter comes out the bottom of your overflow? Also, tooth width has some impact on flow. To get the full 1000gph, you'll need at least 1.5" plumbing from the overflow box.

03-30-2005, 06:04 PM
I have two 1.5 inch u-tubes and the teeth space looks fine there is no problem with water flowing into the over flow just from the first stage to the second.

03-30-2005, 06:25 PM
but what diameter pipe leaves the box going to the sump?

03-31-2005, 04:22 AM
The pipe on the bottem of the overflow is working fine its not getting backed up at all. In the second stage there is a wall that devides where the water flows in to where it over flows over the wall to the drain should I try cutting it down so that there is still enough water in the second stage to keep the siphon in the u-tubes but flows faster?

03-31-2005, 01:48 PM
what are the dimensions of your overflow.....cause I know mine is rated for 1600gph!

03-31-2005, 03:17 PM
(As Brad asked...) What is the diameter of the pipe from the overflow to the sump? That's a very serious variable to consider.

04-01-2005, 01:54 AM
The down tube is 1.5 inch but it is not backing up at all. The problem is from the fist stage to where the water flows over the wall in the second stage to the down tube.