Trying Polyp Lab's "System Reef-resh" this weekend.

[Polyp Lab]

Jaws you are right.

Phosphate levels in an aquarium can not be detected properly with salifert, hagen, aquarium pharmaceuticals etc. kits.

Although fairly expensive to use (and not completely necessary), the only way to get proper phosphate reading is by the use of either

Hanna Colorimeters
Merck Phosphate Kit

I believe the Merck phosphate kit has been rebranded by some aquarium company so it may be more readily available in that version. (I'm not sure of which company rebranded it, we use the original Merck versions at the lab).