Main Drain Question

[tranders]

The main drain on our pool does not seem to have any suction - as it if is disabled. Bought the house last fall and can tell there has been some work done to the pool plumbing in the past, but the specifics are uknown. Mainly it just looks as though pipes were re-routed to support a new filter and/or pump setup. House built in '84. Pool may or may not be original, but is surely not new. Any reason the main drain would be disabled? How can I test it and what is the target in regards to how much suction it "should" have?

DE filter (size escapes me right now)

New 1 1/2 HP pump and impeller

Push pull valve

~20,000 Gal pool

1 skimmer

1 main drain

Thanks in advance. Finally found this forum and there have been some very informative reads!

-Troy

PHX

[ps558]

The main drain on our pool does not seem to have any suction - as it if is disabled. Bought the house last fall and can tell there has been some work done to the pool plumbing in the past, but the specifics are uknown. Mainly it just looks as though pipes were re-routed to support a new filter and/or pump setup. House built in '84. Pool may or may not be original, but is surely not new. Any reason the main drain would be disabled? How can I test it and what is the target in regards to how much suction it "should" have?

DE filter (size escapes me right now)

New 1 1/2 HP pump and impeller

Push pull valve

~20,000 Gal pool

1 skimmer

1 main drain

Thanks in advance. Finally found this forum and there have been some very informative reads!

-Troy

PHX

If the drain is disabled it was most likely due it leaking and it was plugged. They stick a rubber plug in the drain under the cover.

How many pipes come to front of the pump?

are both holes in the bottom of the skimmer open or one open one plugged?

[tranders]

Haven't had a chance to get down and pull the cover to check. There is a single pipe coming up in front of the pump. Both skimmer holes are open.

[ps558]

Haven't had a chance to get down and pull the cover to check. There is a single pipe coming up in front of the pump. Both skimmer holes are open.

It sound like the drain is plumbed to the skimmer and then goes to the pump. The should be a diverter that goes over the holes with a flap in the middle to regulate suction fro, the drain is one type that I can't seem to find a pic of

The other one looks like this

http://www.azpartsmaster.com/Products/Pool...ter__SQDIV.aspx

Its not a big deal to run the pool without these devices, most of my customers don't use them because they like the skimmer pulling more water

[ps558]

Haven't had a chance to get down and pull the cover to check. There is a single pipe coming up in front of the pump. Both skimmer holes are open.

It sound like the drain is plumbed to the skimmer and then goes to the pump. The should be a diverter that goes over the holes with a flap in the middle to regulate suction fro, the drain is one type that I can't seem to find a pic of

The other one looks like this

http://www.azpartsmaster.com/Products/Pool...ter__SQDIV.aspx

Its not a big deal to run the pool without these devices, most of my customers don't use them because they like the skimmer pulling more water

I just that of something if the bottom of the skimmer has a black o ring in it you need the diverter from the link above. If no o ring is present you need the other type that I am still looking to find a pic of

[tranders]

Okay, I will look for these items. No black o ring though.

100% suction on the skimmer does keep the surface nice and clean. But I would like to see what a little suction on the bottom would do too and then decide.

[imnay]

Appears to be some opinion factor here.

While our pool is a 27 ft. round Above Ground it is a hybrid with a gunite floor under our liner and expanded depth to over 6.5 ft. with a sloping floor to a center drain with about 22.5k gallons and we very much depend in our bottom drain and would not suggest that you are better with suction only via your skimmer.

We use the main drain for removal of typical floor small debris which easily sweeps into it - we have never had to vacuum our pool in over 20 years of use. We can partially or totally shut off the skimmer to increase the pulling power of the botom drain when we want to concentrate the pull in that direction and we believe that with both the bottom drain and skimmer working equally with a powerful enough pump we get a much quicker total cycle of our water through our filter making filtration more efficient and the dispersal of chemicals easier.

Obviously the pipe from the bottom drain joins the pipe from the skimmer at some point since you only have one pipe entering the filter. Is your pool surrounded by concrete deck? If there is simple sod/grass I would try to use a thin rigid probe to locate the pipe from the bottom drain and try to discover its' route from under the pool to the pipe that feeds the filter or you could carefully dig near the skimmer to locate its' pipe and work out from there.

Could be that instead of being intentionally blocked it is blocked by some accidental entry of some blocking debris that can be carefully removed even with careful use of a plumber's snake or high air or water pressure - maybe from the filter side pushing toward the drain. We had friends who bought a older home with a pool and the floor drain was blocked with debris which they were able to remove.

Could be there is a buried valve where the skimmer and floor drain pipes join or meet.

As I try to brainstorm this from a DIY perspective the first thing is to know with certainty how your suction plumbing structure is laid and connected end-to-end. Is it possible that the original installing contractor is still in business and could be consulted?? If the pool was added years after the house was built a permit would have to have been pulled from local gov. for the work and that permit should be on file and include info re the contractor.

So long as the pipe is not broken below the pool where it cannot be accessed for repair you should be able to figure out the blockage and, again, our opinion based on our experience is you really will benefit from having a bottom floor drain.

Good Luck

[PaulR]

My main drain is also plumbed through the skimmer; the skimmer basket itself is the flow control, you orient the basket in different directions and it changes the relative suction from the skimmer and drain. There's no diverter flap or valve, it's built right into the basket.

--paulr

[tranders]

Thanks for all your input. Picked up a diverter - the one with a thin black o-ring on the bottom - the one from the link (ps558, thanks). Has a regulator on the bottom (the regulator faces down in the skimmer) which regulates the percentage of suction between the basket and the main drain. I have it set at 50/50 now. So far so good. It moves the debris in the pool into/around the drain. Some gets in and is removed from the pool though (what should my expectation be??). Water circulation is nice with it pulling both the skimmer and main drain.

It seems all I needed was the diverter...for now.