How do we drain a pool?

October 14, 2005 5:38 PM

How do we drain a pool?

My boyfriend has an inground vinyl pool that's developed a gash about four feet below the water level. Patching it underwater hasn't worked, so we want to drain the pool most or all of the way to really get at the hole. (We can't just drain it to four and a half feet down because the hole's at the deep end and we'll need solid footing for repair work.)

So, he plans to set the pump to waste or backwash and turn the motor on. The water will be drawn out through the skimmer and through the drain at the bottom of the deep end. However, once the water gets below the skimmer line, the motor will be sucking air and, he expects, no longer draining from the bottom.

1) Is there a way to shut the skimmer line without shutting the main drain at the bottom of the pool?

2) Is there a better way to do this?

3) Should we do this? Pool FAQs say 'No, don't drain your pool yourself -- call a professional.' Surely some people drain their own pools?

4) Bonus: We don't know how old the vinyl liner is. How do we know when it's time to replace it?

posted by climalene to home & garden (12 comments total)

If you're too cheap to rent a pump, you could simply use siphon action to drain the pool.

Insert entire hose into pool, allow it to fill with water. Seal one end (you might even get away with using your hand) and place it below the bottom of the pool, outside the pool. Remove seal. Watch as free pool drainage occurs! The drainage with end as soon as the water level in the pool meets the other end of the hose, so lower is better.

Of course your city probably has ordinances against this. I lived out in the country where nobody cared at all. If you're going to drain it you probably don't want to drain it onto your neighbours property so try the storm drain instead.
posted by shepd at 5:53 PM on October 14, 2005

Syphon it out with a long hose. It'll take forever, but it will work.
posted by clh at 5:54 PM on October 14, 2005

1) Is there a way to shut the skimmer line without shutting the main drain at the bottom of the pool?

I'm surprised that your pool system doesn't have valves to switch on and off various parts of the suction. But, assuming it doesn't, a raquetball should wedge nicely in the PVC pipe of the skimmer and prevent any air entry.
posted by odinsdream at 5:57 PM on October 14, 2005

Oh, also - if your pump is below the bottom of the pool, you can use the entire system as a siphon. Simply set it up to backwash, begin the backwash, then cut power to the pump and let gravity suck the water out.
posted by odinsdream at 5:58 PM on October 14, 2005

Siphoning is the way to go, if you have access to ground that's lower than the bottom of the pool. Make use of multiple hoses, too, else you'll be waiting awhile.
posted by id at 6:13 PM on October 14, 2005

Do you have the equipment to clean the pool? Hose, etc? If so, that should work. Connect it to the skimmer like you would to clean, attach the hose to the pole, drop it in the deep end and you're in business.
posted by FlamingBore at 6:19 PM on October 14, 2005

I bought a cheap submersible pump for draining a flooded crawl space. You may want to look into somthing like that.
posted by mr_crash_davis at 7:21 PM on October 14, 2005

Put a plug (large rubber cork) into the bottom of the skimmer to drain below the skimmer. I would use a size up so that it won't get sucked in by the pump. A racquetball might be too flexible and get sucked into the line, but a lacrosse ball would probably work if you do not have a plug. Those things do not compress.

I do not think you want to drain the pool too far down. It might cause problems with the liner coming away from the side. The weight of the water keeps the liner in place.
posted by caddis at 7:38 PM on October 14, 2005

Wow -- thanks for the answers so far.

FlamingBore, that's just the elegant, forehead-slappingly simple solution I was looking for. We will try that first, though the seal will have to be pretty strong once the hose-skimmer connection is above the water line.

The Sports Ball of Suitable Size is a great idea, too. That's the backup plan. (Simple pump, no way that we know of to isolate the drains.)

I love the siphoning idea, but yeah, since the pool is inground and the lot pretty flat, there's no easy way to get the external hose end below the water line. I had this great idea a while back: we move the woodpile, dig a deep hole under it, stick a hose down there to drain the pool, and then move the woodpile back so no trace of our caper remains...but it has been gently pointed out to me that digging a ten-foot-deep hole by hand would be close to impossible.

So I guess plan number 3 is renting or buying a pump (which is crazy cheap -- thanks!) Plan number 4 is a meetup/hole-digging party.

We will look further into local regulations, and I welcome the idea of not draining more than we need to. The whole vinyl liner could just warp and disintegrate during this experiment, I suppose, in which case we will go to plan 5: calling a professional.

I'll update this after tomorrow's grand experiment.
posted by climalene at 8:49 PM on October 14, 2005

I've heard horror stories about inground pool walls caving in due to loss of hydrostatic pressure once the pool has been drained. Can any smart folks out there help climalene prevent this disaster?
posted by slookdog at 9:47 PM on October 14, 2005

The walls won't cave in like an Irwin Allen movie, but it's not a good idea to leave your inground pool drained for long. Two seasons ago I drained our gunite pool. Not knowing any better I let it sit empty for 6 months before getting the thing replastered. End result is the sidewalk around the pool is cracked every two feet or so, like spokes around a giant wagon wheel. It's not like the whole pool leapt out of the ground and landed in the driveway, but that hydrostatic pressure thing is for real.
posted by fuzzy_wuzzy at 12:20 AM on October 15, 2005

We don't know how old the vinyl liner is. How do we know when it's time to replace it?

After owning such a pool for 5 years, a good measure is once every 2 years. Any holes or (as you have) gashes would certainly accelerate this process.

"Repair Kits" are, well, to put it as the French do: "Crap".
posted by thanotopsis at 8:10 AM on October 15, 2005