Let's see a picture.

I would love to see a picture since I am about to build a pool with quartz finish and I keep reading about this problem. I'd like to know what it looks like. For me, since we have a natural design and are using a dark finish, I'm thinking it may not be an issue...maybe looks more natural to be a less consistent surface...or I could suffering from false assumptions. I'd like to see what people mean by this.
Thanks,
Judy

If I had it to do over again, I would go with a pebble finish, especially if you want a dark finish. Our 3M was just repaired again. The first time was horrendous mottling from a weak acid start up. Pool drained, acid washed. Didn't work and created a very rough surface. Pool drained again, plaster removed and 3M redone. For the next 6-12 months, this weird gray finish started appearing. They believe it was moisture trapped under the quartz. Drained the pool, sanded, and applied heat. It is lighter and looks significantly better, but if I had it to do over again, I would go with pebble, giving up the oh so buttery smoothe surface for more color control of pebble.

Thank you all so much, but we just found out it is scale which we are told is a much easier problem to correct! We'll see??
Donna

Mottling and Discoloration

The following is a suggested method used by homeowners to help relieve discoloration and rough surface caused by chemicals or chemical imbalance.

As with all chemical treatments, there are no guarantees. This procedure is a suggestion that has worked well for us in the past.

Probable cure is as follows:

Based on 20k-40k gallons

·Add muriatic acid to pool to lower pH to "6.8 - 7" and maintain that level for 5 days.

·The pool must be brushed 2-3 times daily while in this condition.

·Use a combo or a nylon brush.

·This should even the colors in the floor ,and walls as much as possible with white or colored plaster.The roughness ( if it exists) in the pool surface should diminish with brushing (not scrubbing)

·Add necessary calcium chloride and re-test.
·Add necessary cyanuric acid to stabilize.

Here is a link that might be useful: 3m Start up

The pool plaster has to dry out and moisture trapped in can cause grey areas. The curing process of pool plaster has a byproduct called efflorescent (e.g. the dust you can brush off). That dust reacts with the water and raises the alkalinity.You have to keep up with the chemicals and lower the alkalinity almost 5 times a week for the first month. What happens is if you don't keep up then your pool gets a slime layer similar to the one you have see in a water cooler when you leave the water in it for a week.That slime traps the moisture in. I have seen mottling in pebble and quartz plaster.

It's not at noticable in a pebble pool however, due to the composition of the plaster.