Phosphate removers are a gimmick, in several ways:
1. They are sold to everyone, even when they have obvious worse problems -- like low chlorine -- that aren't addressed.
2. Phosphate removers are sold together with phosphate INCREASERS, like most metal treatment products.
3. They are sold as a solution, when at best, they are an 'aid'.
4. They are sold without mentioning the problems they cause, like cloudy pools.

Like most high-margin supplementary products that are occasionally needed or at least helpful, pool stores seem to sell them because it's profitable to do so, not because they are 'worth it' for most people.

But, the products DO remove phosphates, and if you get phosphate levels low enough and keep them there, a pool's susceptibility to algae WILL be reduced.

With high CYA pools, dealing with mustard algae can be difficult, because chlorine levels up to 60 ppm can be required. This is not impossible, but it complicates things, and it's better avoided if possible. I mentioned borates as a preferred 'aid' because it's long lasting, and has no negative side-effects*. But we don't have a lot of data on how effective either borates or phosphate removers are, and if you (a) don't have a lot of phosphates in your fill water and (b) can stay away from metal treatment products and (c) pool store goop, it should not take much, to lower your phosphate levels and keep them low.



*There is some data that suggests it's possible that if (a) you have male dogs used for breeding purposes, (b) who regularly drink from the pool, that (c) the fertility of these dogs will be reduced. That applied to one member of the Pool Forum support team, who used to post here frequently.