Michelle, what is your full chemistry specs? Go to TFP and ask them. The folks are very knowledgable.

Probably calcium build-up. Water chemistry must be off. If it persists, try "No Mor Problems". It's a liquid you can add to your pool

Or :
A couple 3 gallon buckets

a gallon on muriatic acid(MA) or the low fumes version. Same price at Lowes.

a 12 lb bag of baking soda.

three gallons of distilled water (provides the best potential outcome)

a scotchbrite or sponge with a scrubby side.

a sponge

Large rubber gloves. Eye wear is strongly encouraged.

Instructions:

Gloves and eyewear please.

Pool side

Bucket 1: Mix 1 gallon of distilled water, Add 1 pint of MA. This will make an 8-1 mix of acid. Later, it may be discovered this is too weak. Add additional acid until the desired results are achieved, 8 oz at a time. Scotch Brite or sponge with scrubby side.

Bucket 2: Mix 2 gallons of distilled water and 1 lb of baking soda. Sponge in this bucket.

Scrub 10' sections twice with MA solution and then wash it down with baking soda solution. Check the results. If the difference is less than desired, add additional acid as stated before and try it again.

Sometimes, it may take as much as a 4-1 strength to get it done. Better to get there slowly and use less if possible.

Once done, pour the remainder of each bucket in the pool, around the deep end mostly. Rinse the buckets, the partly opened MA bottle, sponges, and gloves in the shallow end.

Remember how much acid you added to bucket 1? Add a about a pound of baking soda per 8 oz of acid. Check the pH and Alk levels in 4 hours (pump on).

Scott

Thanks everyone for your help, my chem #'s are good that's why i was stumped with the white stuff, however I thinksk i had some on the tile before the water was in! i noticed in txmomoftwo's picture she also had it before water, just like when you get the calcium leaching through the concrete shell. My ph is 7.4, alkalinity about 85, my calcium hardness was questionable, pool guy said 324(high-for my pebble finish) pool store tested it and said 262, my question is will the muratic acid or no mor problems stuff lighten or ruin the dark pebble bottom?? Please advise, thanks, Michelle

Yes! I couldn't wait for the pool to be filled so I got in there with all of my gear(it looked like I was landing on the moon...I'm a little overly cautious with acid).

I did what they said above. Dipped a sponge in diluted acid(although, I didn't dilute it that much b/c I knew I wouldn't need that much acid & didn't have any pool water to dump it in when I was finished. I wiped the tiles with the acid soaked sponge all the way around the pool. It did not take that long. They literally SMOKED everytime the sponged touched them. It made the tiles incredibly clean and we have not had any calcium problems since then.

thanks, do you think since my plaster is already done and pool filled, it will harm the pebble bottom, it is a dark bottom and I am afraid the acid will bleach it out??

I'm not a professional, but I wouldn't think it could harm it at all unless your PH gets really off. I have had to add acid to my pool every day b/c the PH keeps rising. Do you add your own chemicals? I would just test the PH before & after you clean the tiles and adjust the PH with baking soda.