Cya high

[JamesW]

I agree with onbalance that the problem of spot etching is usually a plaster quality issue caused the the product or the application.

However, without documentation to establish that the chemistry was maintained properly the entire time, that becomes more difficult to argue.

At this point, draining and polishing with diamond pads might be the best solution.

Then, maintain the chemistry carefully using your own test kit and frequent testing.

Note: Never drain unless you are sure that it is safe to do so.

 

[Jen102100]

@onBalance is the best expert on plaster.

Maybe they can look and give an opinion.

Why would the pool store not be testing correctly? If i buy the correct test kit it will identify the the type if stains

 

[Donldson]

Why would the pool store not be testing correctly?

Why would they be too worried about the accuracy of something they give away for free to get people in the store and buying their products?

 

[JamesW]

Why would the pool store not be testing correctly?

We have found that pool store tests are not reliable.

Post all of the chemistry readings that you have over time so that we can see the history rather than a single point in time.

With many records, we might be able to do some error correction and find some usable information.

If i buy the correct test kit it will identify the the type if stains

We have found that when people use their own good test kit and do regular testing and maintain the correct chemistry they have fewer problems and the problems that do occur are much easier to diagnose and fix.

Stains can happen for many different reasons and we need adequate information to diagnose and provide opinions.

Show the whole pool and the equipment so that we can get a better idea about the problem.

 

[onBalance]

Based on the photos provided in post #9 "Spots on pool" - this is the issue of multiple porous areas or spots in the plaster surface that have slowly deteriorated and dissolved over time to produce those multiple rough areas. The plaster does not appear to be stained. The porous spots are caused by faulty plastering workmanship. JamesW provided the two articles that explain this issue in Post #18.

There is a way to remedy this problem without re-plastering. The pool will need to be drained and sufficiently power-sand the rough pitted areas and make the plaster smooth again. Once the pool has been refilled with water, keep the pool water balanced which will help to keep the plaster looking good for many years.