So I have a hayward standard skimmer. When I bought the house the skimmer weir was missing. I bought a new weir and placed it in. I noticed it requires a higher water level. It seems it dose something to the water, almost like restricts water coming into the skimmer?
Does the skimmer weir (door) have any purpose?
- Thread starter steppinthrax
- Start date
Yes, once debris passes through the weir, it keeps it from floating back into the pool once the pump shuts off.
The door is to increase the amount of water taken from the top of the water where the floating debris are. Without the door on, most of the water is taken to the filter from beneath the surface and would leave a lot of the floating stuff on your water.
Mark
Mark
I'm sorry, but that's pretty much nonsensical. If the bottom drain valve is open as well as the skimmer valve(s) the amount of water passing thru the skimmers is not greater because of the door.
Yes, but what the skimmer does take in will be from the water surface with the weir door in place. Otherwise, the skimmer would pull most of its water from the floor of the skimmer box. It's not the amount of water in question, but where it's taken in. The purpose of the weir door is to force the bulk of the water entering the skimmer box to be from the surface, regardless of the water level in the pool. It's up to the pool operator to adjust the skimmer/lower suction ports mix to utilize the skimmer function correctly.
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That may be true; but we're talking skimmer action here. Velocity, not flow.
The skimmer weir limits the flow coming in to maybe the top 1/2" of water. 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 10 gallons per minute. That's 1.3 cubic feet per minute. That means the flow coming through the skimmer throat will have a velocity of 5.2 ft/minute or .087 feet per second 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 - and water will seek its own level - that water is moving six times as fast or 5.2 feet per second. That's a pretty good clip - 3.5 miles per hour - enough to overcome slight breezes and currents and pull water into the opening. Unless you have a return jet pointing straight at the skimmer throat, any surface debris being shoved along by the return flow will just go right on past the skimmer otherwise.
Look at it from an economics standpoint; if the weir served no good purpose, don't you think they'd leave them out at the factory and charge the same?
- May 22, 2013
- 2,796
- Pool Size
- 12000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Welcome to the forum Mark H. 
As for the door, yup keeps the debris in the skimmer when the pump shuts down. It's like a floating dock staying always at the top of the water so it's pulling water from the very surface. It doesn't increase the amount of water drawn into the skimmer but it does increase it's velocity and you could say it's ability to suck things in that get close irregardless of any bottom drain and however much suction is allotted to that bottom drain. The door makes the most out of the suction it has to draw in debris off the top of the water.
Were are only talking about the water right at the entrance to the skimmer.
As for the door, yup keeps the debris in the skimmer when the pump shuts down. It's like a floating dock staying always at the top of the water so it's pulling water from the very surface. It doesn't increase the amount of water drawn into the skimmer but it does increase it's velocity and you could say it's ability to suck things in that get close irregardless of any bottom drain and however much suction is allotted to that bottom drain. The door makes the most out of the suction it has to draw in debris off the top of the water.
Were are only talking about the water right at the entrance to the skimmer.
I'll take your word for it!
agreed! !