If anything it will make it worse, all the plants, algae's etc are compeating for food, if you kill one (the free floating) it going to leave more food for the other types.
If you have an algae problem you need to find out why , not try and put a bandaid on the syptom. You have to remeber that you need a balance in the tank, light, C02, and nutirants, if anyone of these is out you will get algae problems. The most common is nutirants, through either, over feeding, not enough water changes, or poor water filtering