I have read several threads about completely closing off the main drain. Also seen a few things about closing off one skimmer while manually vacuuming from the other. I would like to try to close the main drain and see if I could get more suction from the skimmers. Want to be sure I do this correctly though. I am going to post a pic of my pump/filter set up now that it is in its permanent location. To close the main drain, can I just twist the knob to the off position? ..and can I do this while the pump is running? Is there any reason not to close the main drain?
PUMP QUESTIONS!
- Thread starter ajbmtb
- Start date
- Jul 21, 2013
- 53,009
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Yes.
yes
No.
Just watch and listen to the pump as you close a valve and see that water continues to flow and the pump does not run dry. If the pump is not getting enough water then open the valves back up.
Ajb,
Your pump has three inputs and each one is controlled by a gray valve.
If you know which pipe goes to the main drain, just rotate that valve to the closed position.
You can close the valve with the pump running as long as you never close all three valves at the same time.
Thanks,
Jim R.
Your pump has three inputs and each one is controlled by a gray valve.
If you know which pipe goes to the main drain, just rotate that valve to the closed position.
You can close the valve with the pump running as long as you never close all three valves at the same time.
Thanks,
Jim R.
Thanks so much, Jim. I turned the valve to the closed position. I have seen a few people say that their pump "runs dry" or "starves" when they do this. Mine didn't seem to have any issues but I am trying to wrap my mind around why this would happen. Would you mind explaining this to me? I caught on to the water chemistry pretty quick but I am struggling a bit with the pump/filter/plumbing!
Depending on the speed that the pump is running, if you have too little flow available for suction and too high a flow demanded by pump it may not get enough water to keep the pump basket full.
The skimmers can generate enough suction that they can start pulling air into them along with all the water…you can hear it when that starts to happen. Some pools have more than one skimmer, some don’t. Each pool has a suction-pump-return equation going on…the fluctuations in pump pressure is a good indicator of this
As i understand it if the pump is starving you need either more flow capacity in your suction or lower speed in the pump to lower the flow capacity in the returns to match
At least that’s how inthink of it
The skimmers can generate enough suction that they can start pulling air into them along with all the water…you can hear it when that starts to happen. Some pools have more than one skimmer, some don’t. Each pool has a suction-pump-return equation going on…the fluctuations in pump pressure is a good indicator of this
As i understand it if the pump is starving you need either more flow capacity in your suction or lower speed in the pump to lower the flow capacity in the returns to match
At least that’s how inthink of it
Ajb,
Normally the problem is the opposite.. the Op wants to know if the main drain is working, so they shut off the skimmer and any other input to the pump, and then they open the main drain.
If the main drain is connected then the pump should get plenty of water and will continue to run... BUT... If the main drain has been plugged or is not open, the pump will very quickly run out of water. All the water in the pump basket is pumped out, and no new water is coming into the pump. This is ok for a very short period of time, but running without water is never a good idea, and can lead to pump damage.
Closing the main drain will often help the skimmers work better as you get a little more water flowing through them.
The real key to good skimming is a weir door. The weir door floats up and down between the skimmer's mouth and the Skimmer basket. If you don't have a weir door it means your skimming will be reduced about 50% or more. Many people think the weir door just prevents the stuff floating above the skimmer basket from come backing out into the pool. That is true, but the main job of a weir door is to 'skim' the surface water into the skimmer.. This why they call it a skimmer. It wants to capture all the stuff that is floating on the surface of the water.
Thanks,
Jim R.
Normally the problem is the opposite.. the Op wants to know if the main drain is working, so they shut off the skimmer and any other input to the pump, and then they open the main drain.
If the main drain is connected then the pump should get plenty of water and will continue to run... BUT... If the main drain has been plugged or is not open, the pump will very quickly run out of water. All the water in the pump basket is pumped out, and no new water is coming into the pump. This is ok for a very short period of time, but running without water is never a good idea, and can lead to pump damage.
Closing the main drain will often help the skimmers work better as you get a little more water flowing through them.
The real key to good skimming is a weir door. The weir door floats up and down between the skimmer's mouth and the Skimmer basket. If you don't have a weir door it means your skimming will be reduced about 50% or more. Many people think the weir door just prevents the stuff floating above the skimmer basket from come backing out into the pool. That is true, but the main job of a weir door is to 'skim' the surface water into the skimmer.. This why they call it a skimmer. It wants to capture all the stuff that is floating on the surface of the water.
Thanks,
Jim R.