Stay away from algaecides! They do more damage than they are worth!

The ONLY one we recommend is Polyquat (preferably 60%). It should say "poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride] 60%". No matter WHAT the label calls it, that's the stuff. You can add an ounce or two a week and that may help prevent algae, but not if you don't maintain your chlorine levels.

Carl