Last year we had a new beautiful liner installed. We received so many compliments, even from the installer who had not seen the liner before. This spring, we had a replacement Raypak 2100 propane digital heater installed. Shortly after the pool was opened, a large stain formed on the bottom. We took a water sample to the pool store and they said there was metal in the water and gave us Pool Stain Treat to remove it. It did, but not long after it reappeared. We were given Pool Stain Treat again, but this time with Metal Free to use the day after. If did lighten the stain considerably, but did not remove it. We went back again, and were give the same products, which is doing nothing. Now we are seeing all kinds of stains forming in the pool.
If there anything we can do to solve this?