I can honestly say I have never had this problem in 20 years. Opened a fairly clean pool a month ago. 2 weeks in we had a nasty wind storm and all the whirligigs from my neighbors maple tree landed in my pool. I cleaned them out pretty well, had another wind storm, more whirligigs. I vacuumed again. Water was clear. Then we had a nasty rain storm my pool turned GREEN and I have had problems since. My chlorine level never gets above .5. My Ph is 7.6, TA is 140, CYA is 50, CH200. I have dumped a lot of shock to no avail. I tried floc didn't drop anything down. Any suggestion??? I need to get this cleaned up. I've already spent a ton of money. And I added a quart of algaecide.