Have had an above ground 24 ft round pool since 2017. But always only put the chlorine tabs in the floater. Never had an issue. Last year liner needed replaced and we replaced the sand in the filter. Opened it this year to it being green. Warmer winter and not closing it clear. Shocked it but read somewhere to add algaecide. So I dumped two gallons of Clorox treat algae in it. Two weeks later it’s still green and have no idea how to fix this or read my levels. Am hoping to get the knowledge to fix this and be better about keeping up with it.