Hi, We've retired to Costa Rica and built a house and put in a small fibreglass pool. We're using the chlorine pucks that were recommended by the pool supplier and everything has been going fine for 8 months or so. They said to put in a new puck every week, which we did. Then we got an algae bloom! We used the flocculant as directed and the water turned clear and blue again. Phew! After a couple months, it happened again. The flocculant cleared it again. Now algae bloom is happening weekly but the chemicals I'm testing for all seem ideal or at least in the normal range. It's frustrating, but I'm thinking I should switch to liquid chlorine.