Anyone using Red Sea Phosphate test?
 

I've used it twice now, and to my eyes, the colour in the sample vile matches the 0.08ppm colour disc closest, but I tested two weeks apart, with several changes of GFO in between. My Hannah checker comes back at 0.00ppm.

Problem is the colour I get in my sample vile doesn't really exactly match any of the colour discs on the wheel of the Red Sea kit very well. Not bright or yellow enough to be 0, but not really green enough to be in the 0.08 and above class. Is that normal? I find their nitrate test to be bang on and super easy to interpret.

We tried it multiple times and the results are always 0.08ppm. Even on a fresh bucket of salt.

We much prefer the phosphorus checker by Hanna.

Yah I tested it on brand new salt water again last night, and the water in my new 4 gallon pico that has no fish and three corals that I haven't fed yet. It showed the same result as my tank water, so either my salt mix is very consistently the same high phosphate level as my tanks, or the colour for 0.00ppm doesn't actually match their colour wheel.