overflow blocked?

anonapersona

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Nov 5, 2008
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I need to change some water to reduce the CYA from ~100 to maybe 50-75-ish.

I put the hose into the deep end of the pool. Hose has the nozzle on it, so it ran sort of slow, didn't find the wrench to get the nozzle off so I left it on. After about 3 hours it had risen 1" to the bottom of the overflow grate. After 6 hours it was at the top of the overflow grate. I guess the overflow is not working -- why would that be?

I was not the homeowner when Hurricane Ike roared through, but my daughter did drop by the home and said the pool was nasty and green and full of debris. No power for several days in that area I think. A week later when we were in town, it was all cleaned up. But, I do suspect that debris got into the overflow.

So, what do I do about it? Continue to fill the pool up to overflow and hope to pressure the debris on down the line? Call "someone" to do "something" about it? Hope it decays and goes away in time?

And, how big a problem is that? If the pool is full to above the overflow is some sort of nasty stuff communicating with my pool from the sewer?

Should I test what happens should the pool actually overflows? I cannot really tell where the water might go, there is a swale full of boulder rocks that may be designed to carry the water away from the house, though the yard generally slopes toward the house. Without running a spirit level I am really not sure how the yard slopes. It is a lot at the end of a cul-de-sac and is diamond shaped, with a mostly square house centered, the pool centered behind the house. The likely water path from the pool to the street is quite narrow as the house fills the lot at that point.

Fortunately, the season for Big Rains is past, but Houston can get 10 to 15 inch rains from time to time and by next spring I will need to be certain that the pool can take a hard rain of several inches without endangering the house.

Advice? Anyone?

Anonapersona, The Woodlands Texas
 
Many pools don't have an overflow drain at all, so it isn't a big problem if your overflow is blocked. If the overflow remains blocked you will need to drain some water out anther way when the level gets too high. That is fairly simple to do. If you have a sand or DE filter you can use the waste or backwash setting on your main valve to drain water out. If you have a cartridge filter there is usually a garden hose style outlet near the filter that can be used to drain water out of the pool.

You might be able to clear the blockage just by letting the water level get higher, or you might need to go in with a drain king or snake.
 
Yes, there is a hose bib attached to the return from the skimmers and after the pump as it exits to the cartridge filter.

Is it as simple as connecting a hose and opening that valve as the system is still running? I guess I would need to override the automatic programming on the Aqualink and turn on just the main pump that goes to the filter. Might damage something if I let the waterfall or Polaris turn on when water levels were low - right?

But, what else do I need to know? Do I turn off any valves anywhere? Skimmers will be useless once the water level drops a few inches, will they be hurt somehow? Or do they just go dry and stop? I saw one valve on each pipe from a skimmer (2) and I think there was another pipe that was from the floor drains.

I would rather try the overflow method again first I think, this may be the first time post-hurricane that the water level has been high and maybe it will simply start the clog to moving. Any point in trying a toilet plunger on the overflow grate? (the mechanics might be difficult given the angle!)

Would it be a bad idea to try to take that grate off and stick my hand in to see if there is stuff at the first bend, if that bend is nearby? Sure as heck don't want to get myself stuck, out there all alone by the pool, with no one living at the house yet to hear me crying in the dark. Is that likely a straight run of pipe or will it snake around to hug the pool decking?
 
Follow up: I tried to fill the pool really high to see if a little extra pressure might help the clog to pass. Should have checked the weather report first. I got the pool level up over the grate for the overflow in about 2 hours and let it get about 2 inches from overflowing. No action at the overflow, drifting leaves showed no inclination to flow that way.

Then the rain began.... in torrents. Pretty soon the pool was near to overflowing and I was eyeing the slope of the decking from the pool down towards the back of the house. In spite of occasional thunder I put on a bathing suit and grabbed a hose to attach to the hose bib after the filter pump. I ran that for maybe 5 hours, just barely keeping ahead of the falling rain.

Had to shut it down at 7PM to go home as we are not living in this house yet. It rained a lot overnight, I sure hope that some of the water got out the overflow, I left it about 2 inches from the top and still covering the overflow grate.

So, a drain king or snake you say? Where does one get these things? How long might I want to get for typical use? Buy or just call a plumber, or call the pool people? Pool company charges $89 just to show up so if buying is cheaper I'll do that.

Anona
 
How to use a snake to clear blocked overflow?

The overflow is blocked, probably hurricane related stuff. Last night's rain convinced me that I really need it cleaned out.

What is a snake? How do I use one? Are there any dangers that I need to know about, maybe relating to unknown pipe size and direction, I assume PVC pipes but not really sure.

I have a 3' drain snake that I picked up at a hardware store long ago, just a flexible metal springy thing on a handle. I can try this first, maybe if the clog is nearby it could help some. Does this work by punching or by twisting? (sorry to be stupid, just no experiance here!)

If it does not, I see two types for sale online at Lowes, drill mounted and handle mounted. How long might we want to purchase? Long enough to go to the front yard (100' maybe)? Or if 25' is not enough, should I just call a professional?
 
Re: How to use a snake to clear blocked overflow?

3' isn't likely to help at all. At a minimum I would get a 25' snake, perhaps something like this one. Any hardware store will have them.

The idea is to push the snake into the drain, while twisting it, and use the tip down in the pipe to tear up the blockage. The main disadvantages are that it takes some effort to thread the snake around corners, and it doesn't always work, particularly when the blockage is further down the pipe than the length of the snake you have.

How long a snake you need depends on how the overflow pipe runs. If you know where the other end of the pipe is you can make a solid guess about how long a snake you will need. Overflow pipes sometimes end up in a dry well underground, in which case it might not be obvious where the other end is. Other times they come out near sewer drains or dry creek beds.

I always try a drain king first, something like this one. They are much less work, though they don't succeed quite as often.

It is also remotely possible that the drain runs to a dry well and the dry well has gotten clogged up. That is rare, and usually only happens when the dry well was not built correctly or is very old. Fixing that requires digging up the dry well, a major project.

When you decide to call in a pro depends on how much you like doing repair work vs how much you like spending money. Most anyone should be able to unclog a drain, but it isn't always very much fun.
 
Re: How to use a snake to clear blocked overflow?

Good Morning,

I have never used a drain king but, from what I've read, you're looking at plumber's snakes which are different. The "Drain King" will seal the overflow pipe by swelling up inside the pipe and then forcing water into the pipe in an attempt to "blow out" the blockage with water pressure. Jason or someone who has used one will be along soon to clarify.

I'm sure one of the Mods will move this thread into the older one. It's a good idea to keep everything together so new people can understand your "story" as it progresses.

Good luck removing the blockage. The plumber's snake you have may very well work or a longer one may work well to......I have a feeling the Drain King is a lot cheaper approach.
 
Some questions. Is there a valve near the output of your overflow and have you opened it? Also, are you sure it's an oveflow and not a skimmer? Many pools are built without overflows so that is entirely possible.
 
waterbear said:
Some questions. Is there a valve near the output of your overflow and have you opened it? Also, are you sure it's an oveflow and not a skimmer? Many pools are built without overflows so that is entirely possible.

Both the inspector (Texsun Pools) and the former owner have confirmed that the little rectangular grate is the overflow. From reading the Deed Restrictions of The Woodlands, I think I recall that pools are only allowed to run overflows into the sewer, that is, not into the street.

I have two skimmers, and I have cleaned them daily and installed liners on them also.

So, I do not see any valve for the overflow. I do know that the first time I added a lot of water, leaving it at the top of the overflow, but morning it was at the bottom of the overflow. So, I suspect there is no valve and it just dribbled out overnight.

Today during a visit to the pool store (for a Wall Whale, an O-ring for the filter, and liquid shock) I asked about the blocked overflow. They suggested a "bladder" which sounds like the Drain King that inflates and uses pressure to push the blockage away. They also said the short snake I have is a good first try, as the blockage might be nearby.

I forgot the snake as I left today on my trip up to the new house. Maybe tomorrow.

Oh, the good news is that all that rain (something over 5.25" yesterday which topped off the rain gauge) plus the 2" of water I added before the rain, plus whatever fell overnight (sounded like a lot!) was enough to drive the CYA down to 30-50, from 100 originally. So, that problem is solved. Now I just tweak the adding of liquid shock with a touch of pucks via the chlorinator to keep it all in check.

Now I need someone to show (or explain) how to use the vacuum for the pool. The little Polaris cannot keep up with storms.

Anona
 
Update, the overflow goes nowhere. It runs back and attaches to a corrugated pipe and runs UP into the landscaping for about 3 feet.

Useless. Worse than useless as it can flow muddy water into the pool where the PVC joins the corrugated pipe.

Should have run the hose up into that before I got the bladder thing.

Anona
 

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