We had our pool resurfaced the end of July, with midnight blue diamond brite. It has been steadily getting more and more mottled to the point where it looks like a satellite image of the planet earth. I have a pool service that comes out weekly and balances the chemicals, as well as vacuuming and sweeping. She has documentation of all her readings. Contractor is telling me this blotching is scale. He said this Is due to a chemical imbalance and that pool needs to run 12 hours a day, Is this normal and what can be done to correct it. There are footprints in the plaster as well, they were not visible in the beginning due to a constant powdery drop on the bottom of the pool. It has taken almost 2 months to get all the powder out, vacuuming to waste weekly.