1) Phosphate remover is expensive while maintaining sufficient chlorine levels is not.

2) Fertilizer contains both nitrates and phosphates so if you've got any planting near your pool or live near agriculture, then odds are you've got this stuff blowing in every now and then so this isn't a one-time removal issue.

3) Pools with high phosphates, but proper chlorine levels, do not have an algae problem. There were two exceptions to this with VERY high phosphate levels reported on this forum (I think it was this forum), but we never followed up to make sure it wasn't something else. Perhaps extremely high phosphate levels may require a somewhat higher chlorine level to keep away algae, but this is speculation.

4) You can accomplish the same thing (i.e. keep away algae) by using PolyQuat 60, though that needs to be added, at least a little, every week.

5) You can accomplish the same thing (i.e. keep away algae) by having 30-50 ppm Borates in the pool.

Try letting the chlorine drop to zero or get really low in one of these phosphate-removed pools and see how long it takes for algae to develop. If it really worked that well, then such removal products would tell you that you could lower your chlorine levels since you no longer need as much chlorine since it no longer has to consume any algae (it's still needed for disinfection at very low levels and needed enough in reserve to not run out). I haven't heard such claims so suspect that chlorine is STILL needed so why not just maintain it at the proper level. Worst case, use a little PolyQuat 60 every now and then for insurance.

Richard