Hi all, I noticed last week a little white line along the water line in the pool figured it was calcium?
So I didnt add water for a week and let the water get down a bit. The white really became noticeable on the tile once it dried out.

Any ideas what this is? I tried using muriatic acid and a scotch brite pad and it didn't make a dent.
The white part is not rough to the touch, its almost like it is a film. When it is wet, you can barely see it.


Thanks very much for any help.

chems

FC 3
PH 7.4 -- (current, but with SWG its spikes constantly.)
TA 110
CH 300
CYA 30







Thanks much!

I've got the same thing in my pool. Similar cleaning results, I have been assuming it's calcium (although my water is nice and balanced, and doesn't have excessive CH...). I've successfully scraped it off with a putty knife, but it was a lot of work and I have smooth tile there so I doubt you could do the same thing without destroying your tile. I'll be watching the thread to see if someone comes up with a good chemical based solution to the problem.

It is actually scale.

If it were calcium it would be around the grout lies. Often when builders plaster and grout they add calcium to the plaster mix to speed up the curing process. Although it is not recommended, when the weather is cold it is pretty much the only way to "set" the plaster.

If it is not built up that much you may be able to remove it with straight muriatic acid. Grab some rubber gloves and a scotch brite scrubbing pad and try it. If not I've also had luck using CLR (Calcium, Lime and Rust remover) which can be purchased at Walmart and most grocery stores.

Purchase some "stain and scale inhibitor" to prevent it from coming back.

Joe

Lower your TA to about 70 or so and keep your pH 7.4 or below. Your TA is one reason your pH keeps going upi so rapidly. Lowering the TA and keeping the pH low will most likely dissolve the deposits over time.

When someone says "Calcium", they usually mean calcium carbonate, which is a type of scale. Calcium would not be seen by itself even if calcium chloride were added to the plaster or grout mix. I'm not sure I understand why you're referring to "calcium" as if it were something different from scale.

If you want to prevent constant PH spikes you will need to reduce your waters ability to rapidly change the PH by lowering your Alk and raising your PH as per Chemgeeks chart found here...

http://richardfalk.home.comcast.net/~richardfalk/pool/CO2.htm

The more carbon dioxide you have in the water as opposed to in the air the more your water is prone to PH changes. Low ALK and high PH help in slowing down your waters ability to PH change. Chemgeek taught me that after I had constantly battled with high PH's and low Alkalinities.. I now live with it and sure enough the PH changes are slow and I am able to catch them in time and slowly bring them down again.

Goyom, were you able to get rid of the white staining on the tile at the waterline? I have an identical situation and would like to know your outcome.

Aside:
For me, I mixed 1:4 muriatic acid in a [former] windex bottle and sprayed the calcium-based stain. It does bubble and dissolve the thick deposits, but the hazy-white line remains even after putting a little scrubbing muscle to it. I was excited about the "set TA to 70" suggestion. But I checked my records and my TA has been consistently between 60 and 80 all season. Yet if anything, the white staining has become worse this season.

Anyways, Goyom, please let us know how things have turned out.

best luck I've had is straight muriatic acid in a pump sprayer, I let it sit for about 10-20min then hosed off, and re-applied if I had to

Full strength muriatic acid had no effect on this stuff. Muriatic acid works great on the thick white buildup that occurs around my waterfall feature, but it has not effect on this stuff. However, I did use a pumice stone on a couple tiles and with only about 20 seconds of scrubbing per tile, 90% of the white stains are gone.

Attached is a picture of my "ring around the pool". I'll post an "after" picture after I scrub. My guess is that I'll probably need 5 or 6 pumice stones to complete the job.

Have the same problem....pool filled with well water very high in calcium. Pumice stone and a bit of elbow grease takes care of the deposits...but they do return. I have not priced water replacement...it would have to come from 200 miles away. Numbers good, pool clear and sparkles. Installation was 4 months ago. Use tabs when we travel and are away more than a few days and BBB when we are home. I try to keep pH around 7.2.
Last numbers 9/4/11
Cl 4
pH 7.5
TA 80
CYA 50
CH 400
Anything else I can do about high CH?
Thanks

Is reverse osmosis available in your area? That can help high calcium.

Did you have any luck with this?

As you may have guessed, your calcium hardness is a little high. I had scaling too with CH of 300, adding borates to the pool completely stopped my scaling issue. My pH was all over the place even with TA in the right spot, the borates totally fixed my problem. My pool was trouble-free all summer long. It's even crystal clear right now with a full bed of leaves in the bottom (I have to clear the leaves out weekly at this time of year).

I have the identical problem (I even have the same color tile). It appeared a few weeks ago following a partial drain/refill to fix my astronomically high CYA level. Does anyone have any ideas/solutions to get rid of the deposit? I've already tried vinegar, baking soda, muriatic acid, and a magic eraser (all separately!) with no luck.

pH: 7.7
FC: 6
TA: 160
CH: 230
Temp: 45F