i use the API liquid test kit, but i really should buy a digital instrument . my tap water has no GH or KH so my ph use to go out of control. crushed coral solved that problem. but im still constantly checking my ph. a while back i was thinking of buying this: http://www.bigalsonline.ca/BigAlsCA...l0/milwaukeeinstrumentswaterproofphtemptester
ive seen those before, i use to have a Pin Point remote sensor thermometer. boy, was it ever crappy. ever time i took it out of the water, i would have to remove the batteries and restart it, if i wanted to put it back into operation..
however, maybe the pin point ph monitor is better! i guess there's only one way to find out!