Hello, new to this forum.
I recently opened our pool for the summer season and have noticed a very gritty substance on the pool walls. It is present where the floor meets the walls and extend 1.5-2 feet up. I have shocked the pool originally and that has cleared the water. I have had the water tested this past weekend for the second time and all reads normal.
I was advised by my local pool store to reduce the pH significantly to bring the water into an acidic state to try and help remove whatever is on the walls. I have tried brushing the substance away but this does nothing. Can anyone tell me what my next steps should be? How did this occur and how fast can this be resolved. Is there a product I can use to remove it from the walls?