Pegasus you did not make me spend money. At this stage in my life I like learning new things and spending money is part of the fun. My biggest problem is interpreting the instructions on some of this stuff. The PH checker came with a packet of powder to check the calibration. It was spot on and I did not have to use the included screwdriver. However it did not say how long the calibration is good for. At least with my refractometer I can use distilled water to see if it is at zero. I already complained about the instructions for Salifert Magnesium test and was surprised to find I was doing it right.
Some of those Hanna checkers are really expensive. I looked at the one for Nitrates and it was almost two hundred dollars. I pass on that one.
As long as the electrode is clean and stored in the storage solution when not in use, it should stay calibrated a long time. I wouldn't worry about re-checking the calibration unless you started getting different readings all of a sudden. Yes, some of the test kits can get a bit confusing, especially when using different types. For instance, I've used Salifert to test my Alkalinity, and Red Sea Pro to test my Magnesium. With Salifert Alk, you use the amount of titrant left in the syringe to find you value on the scale. With Red Sea Pro Mag, you measure the amount of titrant used to find you value on the scale. For the longest time, I was reading the Red Sea syringe just like I was reading the Salifert syringe (I hope I didn't lose you on that one). I couldn't understand why my Magnesium was going down even though I was dosing a large amount daily. After a week of frustration, I realized my mistake. By then, my Mag level was at 2000 ppm. Fortunately, it didn't have any adverse effect on the system, but had it been another element, I might not have been so lucky.
Yeah, the Nitrate checker is pretty steep, but all the others I've seen are in the same price range. I'll have to pass on the Nitrate Checker, too. My Red Sea Pro does a good job of letting me know if Nitrate's tolerable. I checked it yesterday for the first time in 4 months, and it was the same as the last year's worth... less than 0.25 ppm. I can live with that...
