I never got around to getting one. Like the title says? I have a Mastertronic. But, I am fed up with Focustronic gear, with the company with Mr Wang. Focustronic gear could be some of the worst reefing purchases I have ever made. So, how close to accurate are Po4 and No3 on the NP? Is there any maintenance you have to do? Is there another company that makes reagents for them? How often are you calibrating the NP?

