I think my return line is leaking

run53

LifeTime Supporter
May 4, 2010
410
The suspect return line is on top of the steps in my pool. There are no noticeable air bubbles and I don't seem to be losing a lot of water. The bucket test showed no loss other than evaporation. In the past week I've lost 1/2 to 3/4 inch. So if there is a leak, it must be a small one. The only indication is a small line of sand that runs about 2-3 feet out from where the return line is at the pool bottom. I have 3 returns and only see the sand at this return. It's only there after the pump has been running.

Is there a way to confirm the leak and tell where it is? Unfortunately, I have a concrete deck that covers a good portion of the return that I would prefer not to dig up. Not sure what the next step to figure this out is? Do I need to call a leak detection service?
 
Is this the return closest to the pump?

I don't think so. I'm not exactly sure how they are plumbed under ground but it's not the closest in distance. It's the second closest. There is a return that is closer to the pump, but that one is in the deep end and maybe the sand/dirt is coming from that too, but is getting more dispersed? The furthest one away is definitely not blowing sand because it is also in the shallow end and I think I would notice it.

It's really not blowing that much sand but just enough to be noticeable in the shallow end and steps.

If it were the closest return to the pump, what would that be telling me?
 
I just read that air or dirt/sand coming from a return usually means a leak on the suction side and not the return (pressure) side. So the leak may not be in the return line after all. Can anyone confirm this?
 
I went through this not too long ago, losing 3/4 to 1" per day. I tried the bucket test, I tried placing a food coloring dispenser next to the return outlet (pump not running) and nothing went back into the line. I finally hired a leak detection company and they rather quickly determined that there was a void in the plaster behind the light in the spa. The fix was so simple, using a putty epoxy to fill the void, they didn't even charge me extra for the fix. My water bill was very thankful as was I Good luck in tracking this down, but I highly recommend spending the $200-$300 to let the pros find the problem.
 
I went through this not too long ago, losing 3/4 to 1" per day. I tried the bucket test, I tried placing a food coloring dispenser next to the return outlet (pump not running) and nothing went back into the line. I finally hired a leak detection company and they rather quickly determined that there was a void in the plaster behind the light in the spa. The fix was so simple, using a putty epoxy to fill the void, they didn't even charge me extra for the fix. My water bill was very thankful as was I Good luck in tracking this down, but I highly recommend spending the $200-$300 to let the pros find the problem.

Thanks.....that sounds like good advice. However, I'm not even sure I have a leak. I am only losing about 1/2 to 3/4 inch per week. And the bucket test actually shows no leaks after 24 hours. I guess my problem, now is.....why is sand coming out of that return?

Even more confusing is the fact that i thought it was coming out while the pump was running. Well, last night I cleaned up the sand (small amount) then turned the pump off for the night. This morning, the sand was back again (pump never ran at night). It was in the same line on the stairs, under the return. How the heck is sand coming out with the pump off?
 
You could plug the return and make sure nothing comes out of and see if it comes out of another line. As someone said before, it's a suction side leak you have since it's pulling in the sand.
 
You could plug the return and make sure nothing comes out of and see if it comes out of another line. As someone said before, it's a suction side leak you have since it's pulling in the sand.

Good idea. I will try that.

But what puzzles me is how the neat line of sand returns over night with the pump off?
 

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so, I just thought of something. If it really is a suction side leak, then I should be able to isolate it to one of 3 lines. I have 2 skimmers and a main drain. With the use of my Jandy valve and my main drain ball valve, I can turn off each one individually. I would think I should be able turn them off one at a time and see which one makes the sand line stop forming under my return. Does this make sense?

Of course, I have a Polaris Booster pump which sucks off the return lines and then has it's own dedicated return to the Polaris quick connect in the pool. Not sure how that comes into play.

The only other thing I noticed was a very small constant drip coming from the waste of my filter. I have a cartridge filter with DE, so no Multi port-valve on the filter, just a ball valve (which could be the culprit for the leak). Anyways, the leak is tiny. About a pint a day when I caught it in a bucket.
 
I get a little sand on the step too. I wondered if I had a cracked lateral in my sand filter (I see you have a DE filter though...). It filters just fine so I doubt it with such a small amount of sand escaping. Then I wondered if it's just dirt I notice more readily on my white stairs compares to the blue print liner.
Maybe they all release a little dirt that gets by the filter but dirt against a white background is easier to see. I dunno....
 
Problem solved !!!!! :).

Ok this one had me stumped for a couple of weeks.

Clues:

Sand line under return area
No bubbles from any returns
Bucket Test passed, no water lost due to leak
Sand only appears each morning (while pump is off at night)

My original conclusion was suction side leak.

However, yesterday morning I woke up to thousands of tiny ants (sugar ants) floating in the pool. I put two and two together after a few minutes and look under the cantilever edge where the liner locks in and lo and behold I can see the ants coming out into the pool. Also, I noticed they were sending their sand hills down into the pool. Just happened to be right below where the return line would blow out sand (if it were blowing sand :) )

Anyways, I blasted it with ant killer spray and woke up this morning to NO SAND line under return. So no leak after all and I'm a very happy pool owner.
 
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