Hanna calibration kits

[George]

Originally Posted by Reef Pilot

Yes, the phosphorus checker is the most accurate for ultra low range. It was not available from local vendors when I bought my phosphate checker.

However, the phosphate one is more than adequate for my needs esp when compared to the color chart test kits. Despite the 0.04 accuracy spec, I usually get zero readings until my GFO starts getting stale and needs changing. Then I start getting readings above zero, and when it gets to about 0.04, I stir up my GFO in my reactor. Usually after that it drops back down to zero. If it doesn't, I change my GFO, and then it does drop back down to zero. So with those kinds of readings that follow my actions, am more than happy with my phosphate checker accuracy.

Your experience is called consistent. It has nothing to do with accuracy. In order to know if your device is accurate, you have to calibrate it against a known standard. For argument's sake, your actual PO4 could be 0.2 before and 0.1 after (even though your device reports 0.04 and 0).