I have had the following problem for 4 months. PH is dificult to maintain and the pool (15k) uses 3/4 of a gallon of acid a week (even in winter).
Initially the plaster had a tremendous amount of scale from high PH as the use of PH caught the pool company off guard. The company emptied the pool and sanded the plaster (a very smooth specialist finish) back to its original smoothness and color.
However, the pool continues to use acid and the plaster seems to be discoloring again and even becoming damaged. The pool company has been told that the problem is salt and the salt water cholorinator. Can anyone help as this is a big problem.