Tornado in the Skimmer

[DavidD]

I have been helping out a friend of my wife get her pool open this year. She has an 24' round above ground pool. Got it uncovered, cleaned and water balanced but have noticed that every time I remove the skimmer basket, the pump almost sucks the skimmer dry because of the swirling water. Even when vacuuming, I have to remove the hose to let the pump prime itself again. She has informed the that the pump and filter are new, replaced end of last season by a friend of a friends mechanic. He installed a Meteor 22" sand filter with what appears to be a 1.5 HP Pentair pump. Both units appear to be matched. There is One Skimmer and One return and all pipes are 1 1/2" schedule 40. This size pump seems way oversized to me, does it to anyone else? The pressure coming out of the return would probably knock a kid off their feet.
Is there anything that can be done to prevent the pump from loosing prime and/or reduce the suction?

Dave

[cleancloths]

The simplest thing to do would be to partially close a valve on the discharge side of the pump. This will reduce the flow and will also slightly reduce the energy consumption. It does not harm to a pump to throttle the discharge, but do not do that on the suction side.

[matt4x4]

Sounds to me like the pump is very overpowered, she should have a maximum of 1hp for that pool, probably even a 1/2hp would suffice.
There are several other things to look at too though:
1. How much water is in the pool? it should be AT LEAST half way up the skimmer, any lower and the "tornado" will suck in air.
2. How much sand is in the filter? if there is not enough, you will get a higher pressure at the return.

[DavidD]

Excellent ides on the discharge valve if it becomes a problem. I'm figuring the pool is 13k gallons and the filter is a little over 3/4 full of sand. It "appears" that the guy put the appropriate amount of sand in however it's hard to tell. I'm sure another bag wouldn't fit in there. I brought the water level up to within about an inch or so of the TOP of the skimmer opening to stop it from sucking the skimmer totally dry, now there's just the tornado but only when the basket is removed. If it is in place, the pump doesn't seem to loose prime. I did tell the friend not to backwash until the pressure increased 10 psi in the hopes that too would help things. She had been backwashing every time she turned the pump on.
Being the optimistic person I am, I've tried convincing her that the guy probably meant well and had the mentality that "bigger's better" but that this definitely did not apply to swimming pool pumps. Needless to say, she was quite upset that he had done this since she spent over a $1,000 for the pump/filter and to have it moved from under the deck to the side. I think he also closed the pool for her, and did a great job at that. Either way, I think we can make what she has work for now.

[wrinkleigh]

Mine does the same thing -- the answer -- dont remove the basket unless the pump is off.

[duraleigh]

Somewhat off the subject but just for clarification......

Restricting the flow on the pressure side will increase pressure....subsequently increase the work load (energy consumption) of a constant speed pump.

Restricting the flow from the suction side is okay as well. You get reduced pressure, reduced flow, and reduced work load in a constant speed pump

[NWMNMom]

Can you tell me how one would go about restricting the flow on the suction side of the system stated above? I believe that's what we have and BTW, she was overcharged for that by someone by about $400. Thanks.

[posguy]

Ball valve coming out of the skimmer.
Anthony

[NWMNMom]

Oh thanks! We DO have one, I'm so glad we installed that! Actually installed one on each side, just in case work needed to be done.

[drumr]

Mine does the same thing too (as wrinkleigh and DavidD) when the basket is out and I have a 3/4 hp pump on it, no problems with the basket in.