Aquarium Pharmaceuticals (API) Phosphate Test Kit

I suspect most aquarists don't own a phosphate test kit and this is unfortunate because they allow you to avoid algae blooms. Furthermore, in reef aquaria a high phosphate (PO4) level can hinder calcium (Ca) absorption for corals because the PO4 precipitates out Calcium Phosphate making Ca unavailable for coral absorption. Phosphate is also a plant food and you can be inadvertently adding it to your tank through fish food and other products such as Seachem's Neutral Regulator.

The instruction page unfolds to be unnecessarily large so you can cut off the languages you don't need, which reduces its size by half. Comes with a salt and freshwater color card and tests concentrations from 0 10 ppm (mg/L)with the color card increments of 0.0, 0.25, 0.5, 1.0, 2.0, 5.0 and 10.0 ppm. Ideally you want it to be zero to very low levels that should be undetectable with this kit. Product works well and clearly tells me when I need to make water changes.