If algae are constantly eating phosphates then why do we need to remove them right? Well, the simple answer to that is it’s much more cost-effective to deal with the phosphates themselves. All it takes is an application of phosphate remover to clear your pool of phosphates. On the other hand, if we just leave them there and think “oh, they’re getting eaten by algae anyways, I’ll just continue to add chlorine” then you’re putting your pool at risk!
The easiest way to explain it is this way. The more food algae have, the faster it grows. The faster algae grow, the more chlorine demand there is, the faster your free chlorine levels will drop. The faster your free chlorine drops, the more openings algae have to grow and bloom out of control. Now, after seeing that, would you really want to risk a full-blown algae bloom?
Even if you don’t get an algae bloom, you would still end up adding a lot more chlorine than you usually just to catch up with the chlorine demand. More chlorine added means more expenses on your part. And forgetting or skipping just one dose can again turn your pool into a swampy green mess overnight!