How can I have 35 psi AND a leak

Chad_in_TX

Active member
Jul 24, 2019
32
Plano, TX
So for over 6 months I’ve had high PSI (30 starting), that 5 different crews couldn’t figure out. I’ve thoroughly cleaned filters, I’ve bought brand new filters, I’ve had the lines flushed on two different occasions (and nothing came out)…and nobody could solve the high pressure. So I dealt with just extremely low output from my 2 furthest returns (4 total, plus a separate pressure side vacuum line), but never during this time did I leak water.

But now I’ve just dug up a leak that’s loosing 1/4” of water if I run the pool for 4 hours.

So after recently cleaning brand new filters, my pressure still jumped to 35 psi, along with the leak. I can’t wrap my brain around how I can have a leak, but still have very high pressure. Anyone experience anything like this?

background info:
- Pool was built in 93 - 13k gallon
- All new equipment installed less than 2 years ago.
- after digging, found that main drain, skimmer and waterfall plumbing used rigid pvc. Vacuum and return plumbing (leak in the return line) used flexible pvc…..
- simple setup - Pentair 60 DE filter with no backwash, booster pump, and 1 hp pump
 
Hi chad, it’s quite possible the leak is the result of a pinched flex line. This would also explain the high psi even if there was a leak.
How bad is the leak?
What’s the pipe size of your returns?
Can you post pic of equipment and the area you dug up?
 
Thanks for responding! And I have thought about a potential pinched pipe…. I guess it could happen on the return side, but I would think that a pinch would more commonly be seen on the suction side…. For some reason only the vacuum and return lines were plumed flexible. The skimmer and main drain on the left were plumbed rigid. The waterfall line (where you see the flexible running up the back) was done rigid, but like what’s happening now, the rigid line got a crack in it, so we simply ran a flexible line up the back (to avoid having to demo the waterfall)….

I honestly don’t know how big the leak is, because I can’t get to it. As you can see in the pics, the ability to get in there is almost impossible as it runs under the slab of the 5 foot solid concrete waterfall….

Just out of curiosity, as you can see, there’s hardly any space along the edge of the pool and the fence, so would you suspect all of my pipes run under the waterfall and under the pool and simply branch up into each of the return lines?
 

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My guess is that when the pool was constructed the PB did the shell and left the returns to the waterfall guy. I don’t know if it’s the best practice, but waterfall guys use flex. The rocks are actual bubbles with rebar to form the the shape and they use chicken wire and burlap underneath and spray Shotcrete and texture. So the rocks are actually hollow. It’s probably easier to maneuver flex around all the rebar to get to its destination. I have a feeling that maybe one of the returns kinked over time, causing a joint to leak. The returns would all be T off from main return.
To address the psi issue, is the psi 35 when you run the water fall?
Or only when returns are running?
 
My guess is that when the pool was constructed the PB did the shell and left the returns to the waterfall guy. I don’t know if it’s the best practice, but waterfall guys use flex. The rocks are actual bubbles with rebar to form the the shape and they use chicken wire and burlap underneath and spray Shotcrete and texture. So the rocks are actually hollow. It’s probably easier to maneuver flex around all the rebar to get to its destination. I have a feeling that maybe one of the returns kinked over time, causing a joint to leak. The returns would all be T off from main return.
To address the psi issue, is the psi 35 when you run the water fall?
Or only when returns are running?
Okay, I took some videos and here’s what I’m looking at:



Scenario 1) turned off return valve completely and only had waterfall valve open. Yes, the PSI drops to 19, but because of how I had to jerry rig the waterfall pump, there is WAY too much water that comes up at the top. Because of that water starts overflowing everywhere and results in more water loss than the the leak. So within the waterfall (when it functions correctly, there is an additional return which allows for not all the water to come out of the top. Side note: when there is too much pressure on the waterfall return, because the skimmer is next to it (and not opposite it), the skimmer basically becomes useless because the waterfall pushes everything to the back of the pool. This comes into play in a couple weeks when my neighbors trees start dumping leaves into my pool constantly (you can see this in one of the videos).


Scenario 2) Opened the waterfall valve only slightly. This is the adequate waterflow in terms of not being so much that everything gets pushed to the back of the pool, but the overall pressure is still high at 33. That said, if all pipes were working correctly, this is the ideal setting if the waterfall is on (which I usually don’t keep on constantly anyway).


Scenario 3) Opened the waterfall partially, more than scenario 2. I vacuumed up all the water from scenario 1 and after a few hours, there really wasn’t any noticeable water accumulation near the return pipe. Psi is around 22.


So I think what you said is accurate, there’s definitely a pinch in the line. And I’m assuming also a hairline leak that opens up when the return pipe is open 100%. When the pipe is slightly closed up, it relieves some pressure and minimal water comes out.



I’m assuming the hairline crack would be somewhere near the equipment under the the waterfall. But where do you think the pinch would be if I have minimal waterflow from the return near the skimmer (which oddly has always produced the best flow), slightly better pressure on the return on the opposite side, and no pressure on the back returns. I still don’t know exactly how the pipes run (see my diagram and the few photos I have of when the pool was constructed)…

In regards to the pinched line, I’m assuming a pressure test will pick this up, correct? I ask, because when I fixed this pool up a couple years ago (it had been drained for a few months and the equipment was shot), I attempted to do my due dillegence and had a pressure test done. It came back with zero leaks and held pressure. I just want to ensure that whoever I have come out to fix this, I don’t go round in circles with…. Because not one of the 5 crews that came out to address the high pressure ever once mentioned a pinched line (none of these guys did a pressure test, but again, this didn’t seem to be on anyone’s radar…)
 

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First I must applaud you for all the pictures and videos and documentation. Truly is helpful.
So first off it looks like the pb did the returns based off the construction picture. You can see that returns, vac return skimmer and drain were all pressure tested prior to the waterfall being installed.
It’s Hard to say but it looks like the Returns being split may be under the footer for the waterfall and not actually in the bubble.
I do believe 3returns and vac return run along the fence line a foot under.
A pressure test I believe wouldn’t clarify a pinched line, only leaks present.
let’s get more eyes on this, better to get multiple opinions
@ajw22 @swamprat69 @JamesW
 
If the returns are split in or under the footer i would imagine it being difficult if not impossible to fix without ripping out the waterfall. If it was in the bubble you could have a waterfall guy break into the bubble on the backside fix the issue and retexture. But I believe it’s in the footer.
You can also try digging up the returns on the fence line first and see if you find any issues with the returns.
you can also call a qualified waterfall guy or the pb to get some insight on what he thinks.
If you could expose the returns you could reroute the return lines but you would be sacrificing the return line the currently is working the best.
 
What was your filter pressure running before this high filter pressure started?
 
If the returns are split in or under the footer i would imagine it being difficult if not impossible to fix without ripping out the waterfall. If it was in the bubble you could have a waterfall guy break into the bubble on the backside fix the issue and retexture. But I believe it’s in the footer.
You can also try digging up the returns on the fence line first and see if you find any issues with the returns.
you can also call a qualified waterfall guy or the pb to get some insight on what he thinks.
If you could expose the returns you could reroute the return lines but you would be sacrificing the return line the currently is working the best.
I wish I could get a hold of the pool builder. I had some old paperwork on the pool (I moved back into this house after a parent passed away), but he’s long gone and I think passed away himself. This was built in 1993….

seems like this would almost need a camera to be snaked to find. Is that even something a pool leak specialist uses?? Im guessing plumbers do for sewer issues, but then I’m looking at having to get a generic plumber AND a pool specialist involved. Sorry, I’m very green when it comes to plumbing and pools. I know about the bare minimum to keep it clean… lol

I really appreciate your help and suggestions.
 
What was your filter pressure running before this high filter pressure started?
So, a little less than 2 years ago (when I got pool up and going with new plaster and new equipment, after being drained for a few months) it was running at about 22 ish PSI with only the returns. Around 18 when the waterfall was also on.

Then about a year ago it started creeping up… 25, 27, 30 (as my starting points after completely cleaning the filter). At that point there was no leaking, and the lines were blown out twice, but found nothing. For about 6 months my starting pressure has been 30, until a few weeks ago, when the leak started and it stays at 35 (unless the waterfall is on). And like you probably saw in the videos, trees are about to start dumping tons of leaves, so I really need the waterfall off, so the skimmer is sucking in as much as possible. And without the two back returns circulating any water, it’s definitely not very clean at the back of the pool.
 

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Does your DE filter have a multiport valve? If so, set it to recirculate and check the pressure with and without waterfall on. If no multiport, consider removing the filter grids, clean out the filter housing, put the housing back together without the grids installed and check the pressure. This will help determine if your grids are are clogged and possibly needed to be replaced.

In any case, you are going to have to find the leak and/or pinched line and fix it. That may require cutting into the waterfall or possible finding a way to re-plumb around it. If you hav3 to cut into the waterfall, put the waterfall feed line internal again. Seriously consider using rigid PVC and not flex.
 
I would get a bunch of 2" PVC pipe and elbows and build an alternate return on the ground that runs around the waterfall and along the fence line with two pipes into the pool. Connect that directly to your filter.

That will let you see what the normal filter pressure should be. It eliminates the leak. And it buys you time to figure out how you are going to replace your underground return pipes. You can run your pool this way as long as necessary.

The PVC is inexpensive and its just some effort by you or a handyman in getting the materials and assembling it. There are threads here of folks who have done that.

Here is one example...

full


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Update: so I dug about 2 and half feet down under the rock, and am not hitting a pipe (the pipe in the picture is the overflow).

So, I know the rocks basically kind of “fold over” the shell of the pool. I would have assumed the pipes would have been run in the ground close to the shell, but under the rock. When I dig down there, I basically come to the wall, and under the rock is not hollow, it’s sealed up. I know a lot of these types of pools have had problems with their structural integrity, but this Dang this is solid concrete….no hollow spots.

So either they are in that rock, or do they run along the bottom of the pool and up??

I know the issue is probably in/under the waterfall, but I thought maybe if I could find the pipe and dig it up, maybe I would find a link also. What’s strange to me is why they would embed the pipe in the rock so high (if that’s actually where it’s at). That’s definitely higher than the grade of the backyard, and I thought it was important to keep those pipes deep to prevent cracking in winter??
 

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I would get a bunch of 2" PVC pipe and elbows and build an alternate return on the ground that runs around the waterfall and along the fence line with two pipes into the pool. Connect that directly to your filter.

That will let you see what the normal filter pressure should be. It eliminates the leak. And it buys you time to figure out how you are going to replace your underground return pipes. You can run your pool this way as long as necessary.

The PVC is inexpensive and its just some effort by you or a handyman in getting the materials and assembling it. There are threads here of folks who have done that.

Here is one example...

full


full



It’s looking more and more like I may need to do this. The thought of trying to find a qualified person to actually find what’s going on, and then potentially having to jackhammer who knows how much of this pool, makes me a little ill… actually a lot. 😂
 
I feel your pain brotha, that is unfortunate. Maybe do what Allen mentioned above and run your own return above ground until more of definitive answer presents itself. You may even be able to tie into your overflow temporarily if you don’t want the pipe hanging over. I don’t know the cons of that but just giving ideas. Let us know what you end up doing I’m interested.
 
I feel your pain brotha, that is unfortunate. Maybe do what Allen mentioned above and run your own return above ground until more of definitive answer presents itself. You may even be able to tie into your overflow temporarily if you don’t want the pipe hanging over. I don’t know the cons of that but just giving ideas. Let us know what you end up doing I’m interested.
Update:

So, I just rigged up some fish tape w/ an inspection camera and went around the perimeter of the pool. Good news is I didn’t see a pinched pipe, or any massive bubbling up (like chlorine would have degraded the line or something). Granted, I suppose there could be leaks that I just couldn’t see with the camera, but I really wasn’t looking for that…..

At certain points, it was super hard to fish the camera through and on the left return (near the skimmer), I couldn’t go left at all…. It’s super hard to see also, but when the line went through, it was only going towards the right… And for the furthest return, I could only go right… but I’m thinking is that it was actually down. So would it make sense for them to go directly under the pool towards the furthest return (instead of going to the skimmer side and going around a bend)…

So I haven’t cut the return line under the waterfall yet, to put the camera, but what I’m thinking is that line breaks off 3 ways… and at that intersection is probably where the issue is. And if that’s the case, does it make more sense for the intersection to happen under the waterfall, or does that pipe go past the waterfall, within the shell and the intersection happen somewhere under the pool?? My initial though is because I see water under the waterfall, it probably happens there…. OR, that’s just the first issue and if it does go past that, into the pool floor, there’s another issue there…. What do you think?
 

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First off I hope they didn’t run under shell. Usually it’s around the parameter unless it’s absolutely necessary to run under. But the fact that you said the return next to the skimmer goes right kind of throws a wrench in theory. (It’s the return with the most flow)
So original theory was return was T off under footer right side which controlled 3 returns was pinched causing the first return minimal flow and second and third no flow. But the return on left which wouldn’t be impacted good flow.
As seen in picture the x being the suspected pinched line.
 

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So after recently cleaning brand new filters, my pressure still jumped to 35 psi, along with the leak. I can’t wrap my brain around how I can have a leak, but still have very high pressure. Anyone experience anything like this?
35 PSI is about 86' of head at the pump which would be about 25-30 GPM out of the pump and is close to what you are seeing as a leak

Is there any flow rate out of the returns?
 
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Poolbreh

So I haven’t cut the return line under the waterfall yet, to put the camera, but what I’m thinking is that line breaks off 3 ways… and at that intersection is probably where the issue is. And if that’s the case, does it make more sense for the intersection to happen under the waterfall, or does that pipe go past the waterfall, within the shell and the intersection happen somewhere under the pool?? My initial though is because I see water under the waterfall, it probably happens there…. OR, that’s just the first issue and if it does go past that, into the pool floor, there’s another issue there…. What do you think?
Poolbreh should he fish backwards from the closest return line at the pool to the equipment next?

Your X is very close, it has to be. Unless something is changing between each "test."

Maybe we can try killing the skimmer, leave the main drain open. Then lower the water level of the pool just below the jets. Then run the pump. I'm thinking out loud so feel free to shoot me down if I'm going off track here.

If we could kill that skimmer, and waterfall return, while the pump is running with the water just below the pool return, we should reach the same area X more precisely I think. Simply by seeing/reading the flow from the return jets, filter pressure etc.... For starters I would make this a quick test if the returns do not have reasonable flow back to the pool right away. No worries OP you have already done this, lets just do it above the water level now. Not that I don't trust your opinion OP, but no flow, little flow, can change a lot above water. Or not, you may be totally screwed lol. If so I'm curious to know how and why.

If we do not find the same X going backwards to foward, then there has to be a variable we can't see yet, maybe a changing variable. I think Poolbreh has this close to spot on though so I'll ride his shirt tail on this one.

OP
"does that pipe go past the waterfall, within the shell and the intersection happen somewhere under the pool"
I realy do not think that is how your pool is plumbed. Wrong or right I too think the T is at the waterfall or under it. I hope we're right, because under the pool shell plumbing would be bad.. Start searching for companies that do soft digs, GBR digs before you tear apart your waterfall.
 
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