Center Drain for an AGP

How much pitch do you need for a center drain to work properly?


I have always made sure that all of my center drains were the lowest spot in the center of the above ground pool. If you were to ever use the drain for draining the pool this would be important.

If you mean the proper setting for cleaning purposes, I don't think it really matters. The drain will only accomplish two things. It will create circulation from the bottom of the pool so the depth is not a factor there. It can also be use for cleaning if you manually brush the dirt towards the center of the pool. Again, the height of the drain is not a big factor here.

If you have not yet installed the center drain you may be interested in reading my thoughts about center drains in above ground pools.

Above Ground Pool Main Drain

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Center Drain on Used Pool

I bought a used pool with a center drain. If I get a new liner, can I also do away with the center drain and get the automatic pool cleaner?


Yes, I would certainly recommend that you not install the center drain in your used above ground pool. You would be better off just getting an automatic pool cleaner.

Above Ground Pool Cleaners

The only modifications you will need to make on your pool will be in the plumbing to the pump. You will want to do away with the line that goes under the pool. All that is needed is one line that goes directly from the skimmer to the pump. The cleaner attaches to the inside of the skimmer and does not require a separate line or wall opening.

Anytime I acquire a used pool that has a center drain I get rid of it. They are just not the best things for above ground pools.

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Center Drain Plug

by Jim
(Ottawa, On, Canada)

I have a crack in the skimmer valve on my above ground pool and in order to replace it I will probably need to drain the water from my pool down to the level of the bottom part of the valve.

Is there a plug of some sort that I can put over my center drain inlet so that I do not need to empty my pool. Thanks

Hi Jim

It is best if you can do this without draining the pool. I have in the past so it is possible.

My method has been to close off the skimmer. I use a 1 1/2" male adapter with a foot of pipe glued into it. This gets threaded into the bottom of the skimmer with the pipe sticking above water level. That takes care of the skimmer.

The easiest way to plug the return is to put the filter valve in the closed position. That should take care of it.

For the drain you could remove the grate by pulling a couple of screws. A 1 1/2" threaded plug could be inserted inside the drain. As easier method is to take a plastic bag and lay over the drain. As soon as there is a draw from the drain the plastic will suck up for a tight seal, that's the way I do it.

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Center Drain Leak

by Ken
(Burbank, Illinois,USA)

I have an 18 year old 24 foot round above ground pool with a center drain. A new liner was installed 8 years ago.

The last two years my pool has leaked all but 6" of water to the ground. The liner is in excellent condition. I suspect a center drain leak or the pvc piping has a crack.

I am fairly handy. Can the present liner be pulled 2/3 of the way off and then lined up with a new center drain and reinstalled after the center drain has been replaced?

I plan on using an air compressor and put 15 psi in the existing pvc pipe and see if it will hold pressure once an expansion plug is installed in the pool end of the pipe.

The pool is dug out in the middle to 5'6". What are your thoughts? Perhaps a new liner and eliminate the center drain? An 18 year old pool has served its purpose and maybe the best option is to take it down and swim in a lake! Any help is appreciated.

Ken G

Hi Ken

Center drains are seldom the cause for leaks in an above ground pool. The hole is probably around the outer edge some place. I would look very closely at the top of the cove, all the way around the pool.

As the water level gets lower there is less pressure on these holes and they tend to close up, which is why the pool never completely drains. Pin holes in the bottom some where are the next probable cause of water loss.

Pay particular attention to the area around steps or ladders. If you hand vacuum the pool the holes are probably around the outer edge, at the top of the cove. If you use an automatic pool cleaner look very closely in any area where it might get stuck and spend a lot of time.

There is very little chance the liner can be drained and refilled. It will shrink, and because of its age, be unable to refill. Before you drain it completely you might try draining it just far enough to get under the liner and find the holes that way, and then refill immediately. That might work but draining a pool with a liner that old is very risky, you do need to be prepared to replace it if it does not refill properly.

Here are a couple of pages about finding leaks in above ground pools.

Holes in Vinyl Pool

Above Ground Pool Mistakes

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Bottom Drain Line Freezing

by Kara
(Jackson, New Jersey)

We have an above ground pool. Last year, when we replaced the liner - the contractor suggested we put in a bottom drain. He actually closed the pool, so we aren't sure how he secured the drain to keep the line from freezing.

When we went to get chemicals to close the pool - the people at the pool store told us to take the drain cover off, screw a plug into it and then drain the line.

Please tell me there's a more effective way to accomplish this - as the plug idea seems totally illogical to me. And, considering the guy who did it last year didn't have a plug in it....there has to be a way. Thanks.

Hi Kara

Since we do not get Freezing conditions here in Arizona I may not be the most knowledgeable on the subject., but I have never heard of closing off the main drain on an above ground pool.

It is recommended that the filter system be removed and stored out of the weather for the winter. To do this you would need to close the valve going to the drain. This can be done from outside the pool, assuming you have a valve on the drain line, like you should.

It seems to me that if the drain line were to freeze the water would expand back into the pool, therefore eliminating any risk of the line breaking.

Hopefully if anyone knows different they will make a comment with their suggestions.

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Main Drain For Deep End Pool

by William
(South Carolina)

Can I install a filter port on the bottom of a deep end in a sunk above ground pool? If so how?


Hi William

My thoughts about center drains for above ground pools are summed up on the page.

Above Ground Pool Main Drain

I'm not a big fan of them for several reasons. They can leak, and when they do, you have no way of knowing if it's the drain or something else. It will always be suspect any time the pool is loosing water.

As well as automatic pool cleaners work they have become obsolete. There is very little reason to go through the extra labor and expense to install one.

But if you want to, you need to get a Hayward center drain and the necessary PVC pipe and fittings. The Hayward main drain kit is set for inch and a half plumbing. I reduce this to inch and a quarter.

You will install the drain in the center of the deep area. You then trench flat to about a foot outside the pool wall. The pipe then elbows and goes straight up, in the area of the filter system. The drain pipe goes into a three way valve hooked up with the skimmer and the pump.

The drain suction can then be monitored. You can shut the drain off and put all the suction to the skimmer when you are vacuuming. If you are brushing the pool you can shut off the skimmer and push all the dirt into the drain.

There are some pros to having a center drain, but not enough in my opinion, to outweigh the cons.

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