Skip the phosphate remover unless you have algae.

You don’t need to remove phosphates from your pool unless you’re fighting a stubborn algae bloom that won’t die.

Phosphates are everywhere. They blow in from leaves, grass clippings, dirt, even your swimsuit. If you maintain proper chlorine levels (or even a solid non-chlorine shock routine), algae can’t use those phosphates to grow. The chemical reaction is straightforward: enough sanitizer kills algae faster than it can eat. Pool stores love selling phosphate removers because they’re expensive and you have to keep buying them—it’s a recurring revenue stream, not a real necessity.

If you do have algae that keeps coming back despite balanced pH, alkalinity, and adequate free chlorine, then a lanthanum-based phosphate remover can help. It binds the phosphates and makes them settle, so you vacuum them out. But it’s a crutch. Fix your sanitation first. Most people who reach for phosphate removers actually just need to shock harder and run the filter longer.

The one exception: a pool with lots of organic debris and a filter that can’t keep up. In that case, removing phosphates might reduce the algae’s food supply enough to give your system a break. But even then, I’d try a flocculant and a good vacuum-to-waste first.