so i am completely stumped at this point: i had algae at the beginning of the season because of a broken pump, got this fixed and followed the algae advice in pool school, and got rid of it (or so i thought). the last few days, i have seen what HAS to be algae growing on the walls, especially around the pool light and ladder. i can send a pic later if need be. anyway, here is why i am stumped: my numbers have been perfect the last month, i have only let my FC level drop below 4 one time, and i immediately bumped it up to 5. here are my #s tested last night and then this AM:
CYA 50-60 i know i need to get this back up, we've had a ton of rain here
overnight, i had no FC loss. is this still algae that has hung around that i wasn't able to completely kill? is it even possible for algae to survive that long in water that has sufficient FC levels?
any explanation would be very helpful. thanks!