Inground pool leaked down 8 inches overnite!

revell

Member
Sep 23, 2010
10
hello all, first post on this board. :-D

Now down to brass tacks. My mom has an inground pool, approx. 20k gal, built in 1985. The last couple days I noticed it getting greenish so applied proper chemicals to readjust and clear it up, however to no avail, just got darker and darker green. Today, wake up and look outside, the pool went down over 8 inches overnite!

The quandry is there is no evidence of a leak, the ground is not wet anywhere, that much water and you would think there would be some kind of sign...unless the main drain is leaking all the water underneath or a drain line or something under the pool???

It's not the return lines because they are now above ground since the originals froze up about 10 years ago and they are fine.

Could the green color be the fact ground water is getting in? The shell has no cracks that are evident.

Help!
 

RobbieH

TFP Expert
LifeTime Supporter
Aug 30, 2010
4,052
Dallas, TX
My pool leaks 3" per day and I see no evidence anywhere around the pool. Fixing mine Wednesday.

Go to the Pool School section and look at the Leaks entry. Some leaks can mess up your chemistry.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,475
SW Indiana
Check your waste line. A bad multiport gasket can allow water out of the pool pretty quickly.
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
JohnT said:
Check your waste line. A bad multiport gasket can allow water out of the pool pretty quickly.
I agree with John here. Check again? Check the backwash line, etc. 8 inches is a LOT of water to lose in that short period of time. It's a lot more than what you would expect from a leak in an underground pipe.
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
I had a similar problem earlier this year, it turned out to be a blown out PVC elbow in the return line (of course the leak stopped when it made it down to the return fitting height), the pool builder used a DWV drain pipe eblow instead of a pressure pipe elbow, and it held for 30 years, before causing all sorts of headache, leak detection professional to spot the location, jack hammer rental, etc.
 

revell

Member
Sep 23, 2010
10
Well I've watched it all day, hasn't leaked any further, just the 8+ inches overnite which we turned the pump off at approx. 10pm and my mom didn't notice the low level till around 10am this morning so roughly 8 inches in 12 hrs. So based on what I've read and some basic laws of physics, the escape route for the water is roughly at the same level as the current water level, is this correct?
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
revell said:
So based on what I've read and some basic laws of physics, the escape route for the water is roughly at the same level as the current water level, is this correct?
Well, the answer is, maybe. It would be definately at or below where the water is now. Whenever the water pressure equalizes, the water will stop dropping. So, the leak could be below the waterline, but the pressure equalized and the water stopped dropping.
Did the water drop below the returns? Do you have an underwater light?
 

Ohm_Boy

TFP Expert
May 1, 2007
1,344
Orlando, FL
I am getting that 1) you turned off the pump, and 2) some hours later noticed that the water was low.
Does this mean that the water was not low when the pump was switched off, or that it just wasn't noticed?
I ask because a return-side leak could gush a lot of water when the pump is running, but not leak when the pump is off.
 

danbutter

Well-known member
May 3, 2009
105
You aren't on backwash or anything are you?
Is the water staying at the level of the returns?
In other words...did you siphon the water out (without knowing of course) after shutting the pump off?
 

revell

Member
Sep 23, 2010
10
bk406 said:
revell said:
So based on what I've read and some basic laws of physics, the escape route for the water is roughly at the same level as the current water level, is this correct?
Well, the answer is, maybe. It would be definately at or below where the water is now. Whenever the water pressure equalizes, the water will stop dropping. So, the leak could be below the waterline, but the pressure equalized and the water stopped dropping.
Did the water drop below the returns? Do you have an underwater light?

The water level has not dropped below the returns. But, at one return (see pic below) the water level stopped right at the top of the elbow. Now a couple days ago this area would bubble like crazy until you lifted it up just abit, then set it back down. Then the bubbling would cease.



To answer some other questions:

The water was not low when the pump was shut off.

The pump was in filter position.

I even checked at the area where it backwashes out of which is further out in the yard via burried line, all dry.

I'm hoping this doesn't turn into a jackhammer incident as this pool is surrounded by alot and I mean alot of concrete. The new return lines may look a little hokey but they've lasted 10 years thusfar and was a better option than tearing up all that concrete to replace the burried ones.

Plus see how green the water got, it got they way like right now. The water level was still good and tried to balance to no avail. Then the next day, poof, major level drop. This is why I was thinking maybe a crack or something that was allowing ground water in, if that's possible.
 

Shane1

LifeTime Supporter
Apr 29, 2010
621
Buckeye, AZ 85326
So all of your returns are above ground like in the pic? How are the old returns capped off? Are they at the same water level as the new returns?
If the return was bubbling that means air is getting in on the suction side.
I hope you get it figured out.
 

revell

Member
Sep 23, 2010
10
The water never made it down to the old returns which are about 2 -3 inches lower than the new ones. My dad did all this many years ago and unfortunately he passed away last year so I'm kinda winging it on what all was done.
 

revell

Member
Sep 23, 2010
10
Well figured out where the water went. My mom was adding a little water via a garden hose. The hose somehow fell into the pool and she didn't notice it had when she turned the water off and disconnected the hose in the pool from another hose, and there you go, syphoned all nite!

However comma, as didn't run the pump till got it filled back up to proper level, green algae now owns the pool and it's the worst I have personally ever seen. Not only that but the pump burned up. I've read that some algaes namely some of the green species can hurt the filter and I'm thinking it has to be related. Just bought a new pump and am hesitant to turn the juice on till have a professional (only ONE in our area, yes only one pool store chain with only one bloody repair guy) look at it. I'm thinking drain and acid wash, argh.........
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
Revell,

There is no reason to drain your pool. Chlorine kills algae and will turn your pool back crystal clear.

However, you need to read Pool School and start to learn the basics of pool water chemistry and, importantly, read "how to Shock Your Pool"

There are literally hundreds of people here on the forum who will help you if you decide to take that path.
 

gordiec

LifeTime Supporter
Mar 14, 2009
156
Huntsville, AL
Based on some of the swamp pictures I've seen on this board, I suspect that the algae and the pump burning up are unrelated. If you can tell us a little more about your equipment as well as a full set of water test results someone will be along to help. Also you might consider starting a new thread about this, since this one was about finding the leak (glad that you found it and that it was an easy fix!).

Here is a list of what would help:
Pump Size
Filter type

Test results:
FC
CC
PH
TA
CH
CYA
 

revell

Member
Sep 23, 2010
10
Pool size approx 24k gal in ground, 1 1/2hp pump, sand filter, gunnite pool surface.

Lets just say the creature from the black lagoon wouldn't set foot in this sucker! Chlorine is ineffective at this point as the ph is waaaayyyy off. You can't even see the bottom in the shallow end. It also appears there could be sand in there too just from feeling around which I don't want to do a whole lot since I'm not real sure what mutated form of algae we are dealing with. I will test the water and start a new thread.
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
revell said:
Chlorine is ineffective at this point as the ph is waaaayyyy off. .
You dont have enough chlorine in the pool. pH is a bit irrelevant at thid point. Start a new thread, and we cna help you get it cleared. No ned to drain the pool (unless you stabilizer is really high). Get some test results and we can help.
 

revell

Member
Sep 23, 2010
10
Prior to the pump crashing I chlorined the @#%& out of it along with shocking, no help...
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,036
SouthWest Alabama
The only "green" that proper shocking won't clear up is metals in the water and that is very clear it's just tinted green.

You need to read Pool School on proper shocking. Once or twice won't do it. You have to maintain the FC at shock level for your CYA level until you pass the OCLT (overnight chlorine loss test).

We really need to see a set of test results. You say your pH is high but you have yet to post what it is.