I too am a newbie to this forum, thank you. I've been having an issue with green algae, it seems like every other day after I vacuum and brush the walls and floor, the water would be clear for a day then the algae would start to build quickly, when I use the test strip it would show high free chlorine, low ph, alkalinity would be ok, as well as the stabilizer.... I just can't figure it out.....the pool does sit in the sun for about 8-10 hours straight... Thank you for your tips