I have recently bought a new home that has an above ground swimming pool, 15,000 gallons. The pool was not maintained for over a year and was essentially a swamp. I finally cleaned it up with removal of organic material from the bottom, hyperchlorination, algicide, and filtiering 24/7 for about 2 weeks. In this process, I flocked the pool twice on advice from a pool store. Finally I had it totally clear and no stains on the vinyl liner.
The pool store recommended Pristine Blue system, and I followed the instructions and added Pristine Blue and it still was clear with no stains. One day later and after a severe thunderstorm that dumped 6 inches of ran in 2 hrs, the pool had a dark brown stain on the bottom. The stain could not be vacuumed up, and trying to scrub with a soft brush did not work. I took a water sample to the pool store.
The Pool store said it was probably iron and recommended lowering the ph and adding a sequestering agent and running the pump overnight. This is now 3 days later, and the water is still cloudy and the stain is still there. and the pump is still running 24/7. pH=7.4, Cu = 0.3, TA=90.
Any suggestions or recommendations?