First time pool owner- I've lowered the CYA into 60-80 range. FCL AND TCL is 10+ held overnight (highest on the strip test). Alk is within range. TH is a little low. The algae won't go away! I've vacuumed twice in the last two days, used Algaecide based on directions... kept the filter on. I'm wondering if the sand doesn't need changed as it may be spitting vacuumed algae out? We purchased this house in September and the pool was a hot mess!