Yes. And, you can just add some CYA separately. When you buy it, it may be labeled as conditioner or stabilizer. Just check the ingredients. If it says cyanuric or isocyanuric acid, it is the right stuff. You'll probably want to add about 4 lbs. You can either add it to the skimmer and then run your pump 24/7 for four or five days and don't backwash while it is dissolving or you can put it into an old sock and hang it in front of the return jet. Giving the sock a squeeze every once in awhile helps it dissolve faster. But, you'll want to wait until your algae issue if cleared up before you add any.