Hanna Phosporus Checker ULR

Gotten this electronic checker to get better accuracy on Phosphate (PO4) reading compare to D-D Phospate Test Kit.

Test result 114 ppb (Phosphorus) from my shallow 5ft tank containing rocks soak in RO/DI water. Apparently the rocks are still releasing PO4 into the water. :(

Recommended PO4 for SPS tank would be 0 to 0.03 mg/L. Basically need to achieve max reading of 10ppb on my Hanna checker. Still far to go.....

Side by side D-D H2Ocean Phosphate test kit and Hanna Phosporus Checker (ULR - Ultra Low Range).

After reading and research, I managed to obtain formula to convert Phosphorus to Phosphate. Formula as per below:

([Phosporus (in ppb)] x  3.066) / 1000 = Phosphate (in ppm)

Taken my test result as example, it would be 114 x 3.066 / 1000 = 0.349.