You need to post your pool chemistry numbers for anyone to advise you on getting rid of the algae. Include free chlorine, combined chlorine, cyanuric acid (CYA), calcium hardness, pH, and total alkalinity. CYA is particularly important.

It sounds like you have mustard algae which can be pretty tough to get rid of. The treatment is simple. Raise your chlorine to shock level, test the chlorine 3 times a day, and return it to shock level after each test. Repeat this until the free chlorine level holds overnight and the visible algae is gone. Your shock level is a function of your CYA level (see here).

You can get rid of this algae and keep it away, but it will take diligence and patience.