Opened the pool, adjusted the PH, and CYA was at 65. Pool was a bit cloudy but not much and there were areas of a light green brown on the bottom. Slammed the pool to 40 PPM by accident and kept it there for two full days while constantly brushing and using chlorine generator to keep it there. Shut the chorine generator off in the evening and it remained at 40 PPM. I have a cover and the weather was bad so I left the pool covered for the last 4-5 days without the generator running and the level is still at 35 PPM. The patches of greenish brown stuff have reappeared ! This happened all last year so at this point I don't see how it could be Algae. The pool is crystal clear.
What is left for it to be ?
- Thread starter aswetich
- Start date
If the green/brown patches brush off easily then they are almost certainly pollen. If they don't brush off they might be stains of some kind.
I live in Michigan and its only 50 degrees so I don't know how much pollen there is. I also have a electric cover that was closed so even if there was pollen I am not sure how it would get in there. The stuff brushes off in a plum.
Pollen and dead algae are the only two at all likely possibilities. Dead algae accumulating on the bottom is a sign of just slightly too low FC levels, or algae left over from before your raised the FC level.