Post a complete set of current water testing results taken with a drops-based kit (no test strips) and then somebody here can better advise you. I will say that algaecide is a better preventative than taking care of an algae problem that has already started. We also need to know exactly (ingredients) what all you have put in the pool, what type of chlorine you are using, etc. Post back with your numbers and we'll help you get it cleared up.