I found my pool had some minor algae problem about 1.5 weeks before. I followed Leslie's guide to try to remove it by applying "Green To Clean", and 3 times of shock followed by the Leslie's Clear Aid. Now the water looks clean. But, after several days finishing the treatment, I found algae again on the sunny side of the pool. I could brush them off, so they may be dead algae. But, I am so bothered by it. I do maintenance by applying Leslie's perfect weekly and shock every week. Anybody can help diagnose what could be the problem? I sincerely appreciate.