white flakey substance in pool HELP

flchadAugust 18, 2010

I had a pool built going on 2 years ago in FL. No screen, salt cell, cartridge filter, basic pool.

All has been well. Recently, I have noticed a gathering of small, crystal like substances in one spot in the deep end. They are just laying on the bottom. If you stir the water they go all over the place. They are not stuck to the bottom.

If I vacuum them, they come back in a couple days. They are very brittle. They look very much like the calcium buildup you get on the blades of the salt cell, but they dont stick to the pool. they are just laying there. If I carefully take one out of the pool and dry it out, if you handle it it breaks up and turns to what salt would look like.

My pool water chemistry looks right on per the local PaP. No one has a clue what it is. Any advice? thanks!

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Really sounds like calcium. Take a small sample and put it in a little white vinegar. If it dissolves and bubbles, thats what it is.

Quit using Cal-Hypo for shocking or chlorine boosts. Use bleach.

I assume PaP is Pinch A Penny. They aren't national but get enough mentions that I knew who you meant.


    Bookmark   August 18, 2010 at 7:30PM
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It is probably what we refer to as salt cell dandruff.
Usually see it in areas where water is harder. You get build up on the cell, then it self cleans and the flakes are the result.

    Bookmark   August 18, 2010 at 7:57PM
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I will try the vinegar bit. But it isnt building up on anyhting, just laying in the pool. I dont shock my pool at all and have never used anyhtign called Cal-Hypo. Yes I mean Pinch a Penny.

just a pb - this makes alot of sense. It looks like the stuff that is built up on the blades in the past when I cleaned it. I did check the salt cell recently and it was clean.

I hope that is what it is, otherwise I have no idea and no one else seems to either.

Last night, rather than vac them, I netted them out of the pool and dumped them, so we'll see if they return. thanks

    Bookmark   August 19, 2010 at 9:30AM
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Sounds like calcium carbonate. Usually occurrs when the ph rises. Adjust ph to the lower portion of the ph range and it should disappear. Try to avoid ph bounce. Add acid daily if necessary. Good luck.

    Bookmark   August 19, 2010 at 12:47PM
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I agree with all above. I had this issue this year too. I got some out, poured acid on it and it bubbled like mad and was gone so it was CA. Dropped my PH for a while and haven't had issue again.

    Bookmark   August 19, 2010 at 2:07PM
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I add about 3 cups of muratic acid a week to my pool. Sometimes I miss a week if I am out of town, but I am constantly fighting the pH rising from my water type as well as the salt cell. However it never gets above the 8.2 range so there are no gross "bouncing" levels.

So I am a little confused now - if it is ph related, where is this stuff coming from that it just lays on the pool bottom. It isnt stuck to anything. I was under the impression calcium carbonate "grew" in the pool so it would be stuck to the finish.

I was hoping it was more the salt cell dandruff.

    Bookmark   August 19, 2010 at 2:39PM
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You will get better production/service from your salt cell if the ph remains between 7.4-7.6. 8.2 may not seem like a big change, but it is.
You might check other water chemistry items such as Total Alkalinity. If TA is high you will also have trouble keeping the ph in check.
When Salt Generators first became popular in the early 90's I used to put different brands on my pool and then do everything I could to cause the unit to fail. All of the cell units produce the flake you describe when the ph is over 8. Manufacturers still have a ways to go to produce a cell with reasonable longevity. IMO a cell should be expected to last more than 4 years on average. Most who purchase a Salt Gen. will spend $2000 on the unit in 4-5 years including purchase price.

    Bookmark   August 20, 2010 at 11:47AM
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Thanks again for all the info. I am going to keep a better eye on the ph now as well as CH and the alk.

I guess one bottom line question I havent asked: is there any harm to the pool to come from these flakes, especially any harm to the finish?

    Bookmark   August 20, 2010 at 12:40PM
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Should be no short term harm. Flakes can plug filter and finger screen in the pool cleaner line. I've never seen calcium in this form stick to the plaster, but it is probably possible.

    Bookmark   August 20, 2010 at 3:52PM
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I had the same thing the whole time I used a pool service - my PH was usually closer to 8.2, I've discovered if I keep mine closer to 7.6 I have no calcium dandruff, as soon as it goes over 8 it appears within a day or so. I add acid a couple times a week now and aim for the lower end (between 7.2 and 7.6) - everything runs much more smoothly.

    Bookmark   August 24, 2010 at 3:29PM
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