Help me understand Skimmers


Jun 7, 2008
I have two skimmer boxes and two holes in each skimmer.
The back holes have suction when the pumping is running.
Then there are holes in front of each back hole that appear to go about 8-10 inches down into nothing, capped or just never opened??

There is a peice of hard plastic that rotates 360 degress to cover one hole at a time.

I was told that I should use the flap to cover the suction hole on the far skimmer basket about 80 degrees when I do my manuel vaccuming.

Is this the only time I should mess with this flap?
Why are there two holes?
Is there anything else I need to know?
Will batman get there in time?

All comments welcome


LifeTime Supporter
TFP Expert
May 3, 2007
Pleasanton, CA
There are two holes in the skimmer because sometimes, the other port is connected to the main drain. If you don't have a main drain or it has it's own separate line, then you don't need the other port in the skimmer.

As for the flaps, usually you want them wide open but sometimes you need more suction on one of the skimmers so the other skimmer suction is reduced by closing the flap. After vacuuming, you should open both flaps 100%.


LifeTime Supporter
May 28, 2007
Fayetteville, Arkansas
I have a similar set-up. One of the holes is capped and never used in both skimmers. I close the plastic cover when I'm vacuuming the pool either manually or with a skimmer driven type of a device. It gives you more vacuuming power when all the water is channeled through one skimmer. You may have to make small adjustments at the pump in order to get the right suction power level for your particular needs. For example: if I put full force through one skimmer my pool cleaner will 'stick' and not move very much at all. If I back it off some at the pump, it'll 'let go' of the floor and move right along. As far as to why there are two holes in your skimmers, I can only guess it's for an application with more features. Hope this helps you out.