Skimmers missing weir doors

Apr 27, 2020
I have a similar issue. Number one we have no weir doors our pool guy threw those away and said we didn't need them? Two the skimmers worked fine the first two months and now seem like they barely move? You can see some debris going into the skimmer and sometime down through the line but not near what it was a month ago. Could it be clogged or need to be adjusted and how? We have tiny gnats all over the pool every morning and I hand skim but the skimmer doesn't pull those in or pull enough to pull them down through the line.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

Weir doors are what makes skimmers work. Is this a new pool?

Please fill out your pool's signature so that we all know what you have before trying to answer a question.


Jim R.
Last edited:

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
Rancho Cucamonga, CA
The alternative to a weir door is a "floating weir" skimmer basket. Your skimmer basket would be made up of two parts. The inner sleeve, which moves up and down, is designed to float on top of the water to create the skimming effect.


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
You need weirs for skimming. From just about a year ago

Think it through. Water seeks its own level.​
As the pump sucks water out of the skimmer well, pool water flows into the skimmer well through the throat to maintain the level. So far, so good?​
If the cross section area of the skimmer throat is 3"X12", that's .25 sq ft. Let's say the skimmer is pulling a measly 100 gallons per minute. That's 13 cubic feet per minute. That means the flow coming through the skimmer throat will have a velocity of 52 ft/minute to maintain the water level. Now reduce that opening to 1/2"X 12". That's 1/6 the area so to maintain the water level that water is moving six times as fast or 312 feet per minute. That's a pretty good clip - 3.5 miles per hour; enough to overcome slight breezes and currents and pull water into the opening. The weir is critical. The skimmer weir limits the flow coming in to maybe the top 1/2" of water. Less water above the weir means faster current. More water above the weir means sluggish flow.​
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