Saggy liner / wrinkles forming - clueless

[maruscmn]

So I am on my 3rd season with my pool. It is 17200 gallons run with a SWG. Everything has been going well until about 3 weeks ago where I noticed my liner above the water line was "sagging" - in addition the liner looked bumpy in some areas. It started to form directly across the skimmers (returns). First a little wrinkle formed, and then it spread. It should be noted I am heating the pool with the Hot Spot Energy Pool Heater (set at 90) The liner company is blaming it on the chemicals however I am religious with my testing (TF-100) and beyond me shocking the pool one time, the chemicals are right within range. The pool receives direct sunlight for 10 hours a day and I have an auto cover on it. Kids swim daily in it. The following is the history from this season:

Date	pH	Free Chlorine ppm	Total Chlorine ppm	Combined Chlorine	Alkalinity ppm	Calcium Hardness ppm	Cyanuric Acid (CYA)	Water Temp (F)	Comments
4/4/2016	7.2	0	1.4		112	331	11	55
4/7/2016	6.7	0	0.7	0.70	112	326	-	56
4/11/2016	7.4	0	0.4	0.40	193	317	66	56	Pool store gave me 7 bags of burn 35 which screwed up TA
4/14/2016	7.4	9	9.5	0.50	230	315	60	57
4/18/2016	7.2	2	2.5	0.50	150	320	60	58	Added 34oz of muriatic acid
4/19/2016	7.1	2	2.5	0.50	130	320	60	59	Raising Cl generator from 17 to 20%. Added 40 oz of muriatic acid
4/21/2016	7.1	2.5	2.5	0.50	120	300	60	66	Added 20oz Muriatic acid
4/24/2016	7.1	2.5	2.5	0.50	120	300	60	67	added 40oz Muriatic acid, raised Cl generator to 25%, added 1.75 lbs CYA. Used Superclor on cell
4/25/2016	7.2				120				added 1.31 gallons of Muriatic acid
4/30/2016	7.2								Added 25lbs of Boric Acid
5/8/2016	7.2	5.5	6	0.50	80	300	65	72
5/10/2016	7.2	3.5	4	0.50					Chlorine generator updated to 20%
5/14/2016									Cleaned filters. Fixed slide piping.
5/21/2016	7.2	6.50	7	0.5	80	300		68	pool open all day
5/22/2016		7.00	7.5	0.5
5/26/2016	7.3	5.00	5.5	0.5	80	300	65	78	Chlorine generator at 17%. pool opem at 1:00 - sunny. Added 1.5 lbs of CYA
5/29/2016	7.3	5.50	6	0.5	80	400	65		Added 1 lbs. of CYA. CL generator at 20% The FC was tested at 1900 hrs and was 4.5 - all day sun and swim - tested morning and FC dropped to 3 - upped CH to 50% with pool open
6/4/2016	7.3	6.50	7	0.5	80	400	80	81
6/5/2016	7.3	7.00	7.5	0.5	80	400	80	82	4 kids, 4 adults, sunny 80 degree day. FC started at 7. Superchlorinator was running until 6:00pm.
6/10/16	7.3	4.00	5	1	80	400	80	88	added 1.2 gallon of bleach and upped the CL generator to 40% also superchlorinated generator
6/12/16	7.3	4.00	7.5	0.5	80	400	80	91
6/21/16	7.3	3.50	4	0.5	80	400	80	91	Added 100oz of bleach
6/22/16	7.3	5.50	6.5	1	80	400	80	91	5 Kids 4 adults. measued at 7:00 pm
6/23/16		3.50							Added 363oz of bleach to get the FC to 17 to SLAM. tured cl gen down to 10%. Checked CL at 1830 and FC was 22.
6/24/16		17.00						91	Added another 363 to continue to slam pool. 7 kids in pool. 5 adults.
6/25/16	7.4	24.00	32	1					Max CL level - overnight test drop completed
7/2/16	7.4	8.50	9.5	1
7/11/16	7.5	7.00	7.5	0.5	80	400	80	91
7/14/16	7.5	2.00	2	0.5	90	400	80	88	Added 80oz of bleach to bring Cl to 5ppm. CL generator set at 20%

I have additional pictures I can upload.

So is it that my pool is just getting to warm under the cover? Could it be a small hole I just have not yet found? When my water level is high it seems to exacerbate the problem. The liner company is standing by my chemical levels as the issue. Anyone have any thoughts?

V/R

Mike

- - - Updated - - -

http://i1164.photobucket.com/albums/q573/maruscmn/Pool/IMG_7178_zpsclov6rw2.jpg

http://i1164.photobucket.com/albums/q573/maruscmn/Pool/IMG_7174_zps0ojdbx44.jpg

http://i1164.photobucket.com/albums/q573/maruscmn/Pool/IMG_7176_zpsn05ci4au.jpg

 

[borjis]

I don't see any sagging..can you elaborate on what you mean? (I was expecting a photo of the liner off the track)

What happened on 4/7 to get the ph so drastically low?

When you add the acid, how are you doing that?

Is is possible the wrinkles are from ground water? I've seen posts here with other folks having those and were
able to get them out with a plunger.

Gorgeous pool by the way.

 

[maruscmn]

I don't see any sagging..can you elaborate on what you mean? (I was expecting a photo of the liner off the track)

What happened on 4/7 to get the ph so drastically low?

When you add the acid, how are you doing that?

Is is possible the wrinkles are from ground water? I've seen posts here with other folks having those and were
able to get them out with a plunger.

Gorgeous pool by the way.

Thanks! I will have to post a video of us building it at some point (captured on gopro time lapse) Took 8 days - it was a learning experience!

See this image
http://i1164.photobucket.com/albums/...psclov6rw2.jpg

See how it is bulged at the top (rounded)

As for the Ph being low, that was an error as recorded by the pool store equipment - i need to flag that - that was really the last straw and forced me to get the TF100!

I have a swim pump (Badu jet) that I run while slowing pouring the acid around the pool. I haven't added acid since 4/25 (that whole process was to bring down the TA which was screwed up by the pool store) Since then the Ph has been rock solid. During that time the Ph would go down to 6.9-7.0 but i would run my badu jet for a couple of hours at a time and the ph would rise to 7.2.

We really have not had much rain compared to the previous years. I tried the plunger with no luck - couldn't get a good seal.....

 

[duraleigh]

Is your liner bulging/sagging only above the waterline?

 

[smforte]

Zoomed in on your pic. Looks like lots of wrinkles on the wall and one big one on the floor? Yikes!

 

[maruscmn]

Is your liner bulging/sagging only above the waterline?[h/QUOTE]


Yes. Below the waterline are all wrinkles.

 

[MarianParoo]

Did you by any chance have a big rain and get a lot of water on top of your auto-cover that wasn't pumped off right away? The weight of the water on top of the cover can force the pool water level up and behind the liner.

 

[maruscmn]

Did you by any chance have a big rain and get a lot of water on top of your auto-cover that wasn't pumped off right away? The weight of the water on top of the cover can force the pool water level up and behind the liner.

Yes we have had lots of rain but I keep a pump on top of the cover and it rarely cant keep up. I am starting to think it may correlate to the amount of activity in the pool - maybe a small hole right at the waterline? I marked the water line last night and noted an 1/8th to 1/4 drop in water - but the outdoor temp is 90+ so i am not sure if that is natural loss. thanks all for the suggestions as i believe in the power of group knowledge!

 

[PAGirl]

I'd recommend a bucket test. Could there be leaks around the skimmer?

 

[maruscmn]

I'd recommend a bucket test. Could there be leaks around the skimmer?

You know I completely missed the bucket test! I will do that when I get back!

as for the skimmer I highly doubt it because the wrinkles are on the opposite side of the pool.

 

[borjis]

When they installed the liner did they mention if it was a tight or loose fit?

I've read that loose fitted liners have the most issues and could be the cause of the wrinkles and are
often the cause of liners pulling out of track.

When mine was installed (a custom measure had to be done) they said it was a tight fit but
that can be a good thing if nothing goes wrong once it's filled.

 

[maruscmn]

When they installed the liner did they mention if it was a tight or loose fit?

I've read that loose fitted liners have the most issues and could be the cause of the wrinkles and are
often the cause of liners pulling out of track.

When mine was installed (a custom measure had to be done) they said it was a tight fit but
that can be a good thing if nothing goes wrong once it's filled.

I installed the liner in 2014 and it was a great tight fit (custom ordered) In fact up until this issue started I had maybe one or two 3 inch wrinkles in a corner.

 

[BestJoeyEver]

I have nothing to contribute to the liner convo, but wanted to comment that your pool looks awesome!

Sent from a tiny keyboard.

 

[pondfishr]

Our last liner did the exact same thing before we replaced it although it took it 6-7 years before it started. I think in our case it was from the PH being too low. We had a chlorine puck pool / powdered shock. The cya got out of control and we never could get our ph to stay up.

 

[maruscmn]

Ok so a little update: One. The bucket test confirmed there was no leak; Second, I've been in contact with GLI pool products and provided them with all of my chemical records since the pool was built. The lowest the ph has ever been is 6.7 for a short period (1 day). After speaking to them and explaining how my pool was set up, we (customer service rep) and I determined it was not caused by the chemicals.

GLI has a theory regarding pools with auto covers that are in a lot of direct sunlight. They believe the water at the top gets super heated under the cover (My pool is very warm) which outgases the Cl from the pool water. Normally I try to keep my CL 3-5ppm. GLI believes the CL levels rise to a much higher level causing the liner to break down and sag. They recommend keeping the Cl at .5ppm or the cover off for the majority of the day - neither of which is possible. They are currently taking to their management to determine what to do in my case. They also said they are sending out a service bulletin to their distributors telling them of this issue.

I will let all know what is the outcome. I even offered to swap out a brand new liner I have sitting in my basement - only difference is it is 1' shorter (36' vs 37') I should just sell it...

M