pH monitors
J G,
They work great, but remember they have to be routinely calibrated if you are going to depend on the results. The probe will also need to be replaced every year or two. Make sure you order some calibration standard for it if you get one. For really accurate results you really need to calibrate at two points, probably pH 7 & 10. If you are going to be using it in a continuous mode, you'll need to clean the film that develops on it routinely.
I've never really used one for my aquariums but have a lot of experience in using them in laboratory and wastewater applications.
My personal opinion is that unless you are using a calcium reactor I'm not sure a pH meter is really all that useful. If your buffer is staying where it should be its probably not all that useful. I have seen some calcium reactor set ups that have it as part of an automatic feed back system that cuts the CO2 on and off.
Gary
Gary
125 SPS, 75 gal. LPS/softie reef, 9 gal. Nano