Grey stain on pool liner and now ladder

Stains on the pool surfaces, pool equipment
or on the swimmers, or off-color swimming pool
water. Discolored but clear pool water.
nikkih10

Grey stain on pool liner and now ladder

Postby nikkih10 » Sat 13 Nov, 2010 23:27

Hope that someone can give some advice on our recent pool problem.
About two weeks ago I noticed that 85% of our pool liner was turning a very light shade of grey (a green/grey).
We have had the pool for 15 years now & this has never happened before. The pool has always been low maintenance. I keep it crystal clear every winter & summer.
Basically only need to use Chlorine. Have used some dry acid when required or Alkali increaser if required, but in 15 years that may have totalled 5 times. I also use an algicide every three months or so. One other thing of note, I use dry chlorine, that soaks in water before I throw it in. When any residual flakes land on the stain, it turn it a much darker grey.

The stain has also attached itself to the pool ladder and now the walls of the pool, brushing the bottom of the pool seems to make no difference. I did get a scouring pad & rubbed the ladder, that seemed to get the stain off, but it took a lot of pressure.

I have had the water tested, it said very little chlorine was there & also it needed an alkali boost. I followed the pool shop guys instructions. Still the stain remains. Another pool guy I spoke to had very little idea also.

I'm hoping someone has had the same issues & can let me know the soloution they found. To me it looks like some sort of chemical inbalance.

Thanks

Ian


Allen G Myerson

Grey stain on pool liner and now ladder

Postby Allen G Myerson » Sat 13 Nov, 2010 23:56

It's probably copper. What are the ingredients in the algaecide that you use? Do you have a heater?

Have the water tested for copper. Put some ascorbic acid on a small test spot and see what effect that has. Try some vinegar on a sponge to see if it will lighten the stain. What are all of your chemical readings?
nikkih10

Grey stain on pool liner and now ladder

Postby nikkih10 » Sun 14 Nov, 2010 05:11

Allen,
the algecide is all gone now, but is a copper sulphate based product. There is no heater in use.
I tested it on Saturday with a test strip, it showed everything was fine, except Satbilser a bit low.

Ian
Allen G Myerson

Grey stain on pool liner and now ladder

Postby Allen G Myerson » Sun 14 Nov, 2010 11:05

Try the tests that I indicated. You can get ascorbic acid from your local pool store. Example . Or from here . You can put the ascorbic acid in a clean cloth, like a sock, to hold the ascorbic acid on the stain for a little while.

If you can provide the following information, it will help.

Free chlorine
Combined chlorine
pH
Total Alkalinity
Calcium Hardness
Cyanuric acid
Temperature

You really need to get a good test kit, such as the Taylor K-2006. Test strips are not reliable or accurate.
Copper Iron
Allen G Myerson

Grey stain on pool liner and now ladder

Postby Allen G Myerson » Sun 14 Nov, 2010 20:25

Note: Vitamin C is ascorbic acid. You can crush up a few tabs of vitamin C and use the powder for a spot test.
nikkih10

Grey stain on pool liner and now ladder

Postby nikkih10 » Mon 15 Nov, 2010 21:19

Called into the pool store to get my water tested properly, but his machine was out for repair.

He didn't have any ascorbic acid, as the chemical factory across the road from work didn't.

The pool shop sold me a product to try called Metal Magic, approx $30.
He said to run the filter 8 hours per day for a week to see if this helps, don't back wash during this time.

Will let you know how that goes.

Regards,

Ian
Allen G Myerson

Grey stain on pool liner and now ladder

Postby Allen G Myerson » Tue 16 Nov, 2010 01:57

Metal Magic is a HEDP (1-Hydroxy Ethylidene-1,1-Diphosphonic Acid) chelating agent. It might help. You might need a reducing agent to fully remove the stains. Crush up some vitamin C tablets and allow the vitamin C powder to sit on a small area of the stain to see what effect it has.
nikkih10

Grey stain on pool liner and now ladder

Postby nikkih10 » Wed 17 Nov, 2010 01:10

Allen,
I have just tried a Vitamin C pill, nothing happened, I took the ladder out of the pool Which is discoloured. When I took it out & now that the pool is crystal clear, the stain is looking more like a a green/brown colour.

I have taken some pictures that I can send you, if you can post an email address, not sure how to post pics here.
The filter ran all day while I was at work, doesn't look like the metal magic has made any difference.

If I scrape some of the coloured material off would a pool tset at the shop show what it is?

Cheers,

Ian
Allen G Myerson

Grey stain on pool liner and now ladder

Postby Allen G Myerson » Wed 17 Nov, 2010 06:50

You can post the photos at http://photobucket.com/ and then post the link here. The green is almost definitely copper from the algaecide. The brown is probably from iron. Have you had any algae?

If you can provide the following information, it will help.

Free chlorine
Combined chlorine
pH
Total Alkalinity
Calcium Hardness
Cyanuric acid
Copper
Iron
Temperature

Are you able to scrape off the stain? Try some vinegar on a small test spot to see what effect that has.
nikkih10

Grey stain on pool liner and now ladder

Postby nikkih10 » Wed 17 Nov, 2010 21:16

Allen,
test results below. Copper, almost no reading, it was .02, he had to change it to .1 to show a result.

Free chlorine 0
Combined chlorine -1
pH 7.4
Total Alkalinity 68
Calcium Hardness 242
Cyanuric acid 49
Copper .02
Iron -1
Phosphate .2
Total disolved solids 591

My pool right now is crystal clear

The guys said that adding 4kg of Alkalinity increaser & 3.4 ltrs of liquid chlorine is required. I showed him the pics of the pool showing how random the stain is, he didn't feel that the above additions were going to fix this problem.

Any thoughts?, he said he could get a scraping tested at a cost of $100 or so.

Cheers,

Ian

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