If you have the money, buy BlueLab ph pen. If you're on a budget, I have these Etekcity pens from Amazon for about $7 each. They work great. Put some clear packaging tape over the LCD to prevent water splashing in.
I have the Milwaukee ph-006 mentioned earlier. I don't like it compared to these $7 pens. The calbration screw is *way* too twitchy. And, the thing has gone bonkers on me a few times. Readings go wild. I have to let it sit uncapped for a day to dry out, then rehydrate, recalibrate before the next 3-4 uses, then it works ok for 1-2 months before going bonkers again. The $7 pen has been much more reliable by comparison. At that price, I can keep two in use at all times, have one as a spare.
Eventually I'll buy a BlueLab.
You'll need calibration, storage and cleaning solutions. The Etekcity comes with calibration solution (usually). Pour the powder into distilled water. I was skeptical of the accuracy of that kind of self-made calibration solution. But, it compares exactly to the bottled cal. solution I have. Keeps forever too. So, that could save you some money.
I strongly suggest buying a Control Wizard Accurate 8 soil ph probe for $60. Mine helped me out a lot. You can always measure runoff ph but that's not too accurate unless you follow a rigid protocol like the NCSU Pour-Through Method. The probe is cool because you can check soil ph at different stages of drying, not simply when it's completely wet like runoff. Soil probes aren't tremendously accurate either. But, this is better than those 2-prong cheap meters. I like it because I can adjust my soil's starting ph a little with hydrated lime (to raise) or aluminum sulfate (to lower). Not much of either one. Maybe 3-5g per gallon of soil to move it 0.3-0.5 ph.
I have the Milwaukee ph-006 mentioned earlier. I don't like it compared to these $7 pens. The calbration screw is *way* too twitchy. And, the thing has gone bonkers on me a few times. Readings go wild. I have to let it sit uncapped for a day to dry out, then rehydrate, recalibrate before the next 3-4 uses, then it works ok for 1-2 months before going bonkers again. The $7 pen has been much more reliable by comparison. At that price, I can keep two in use at all times, have one as a spare.
Eventually I'll buy a BlueLab.
You'll need calibration, storage and cleaning solutions. The Etekcity comes with calibration solution (usually). Pour the powder into distilled water. I was skeptical of the accuracy of that kind of self-made calibration solution. But, it compares exactly to the bottled cal. solution I have. Keeps forever too. So, that could save you some money.
I strongly suggest buying a Control Wizard Accurate 8 soil ph probe for $60. Mine helped me out a lot. You can always measure runoff ph but that's not too accurate unless you follow a rigid protocol like the NCSU Pour-Through Method. The probe is cool because you can check soil ph at different stages of drying, not simply when it's completely wet like runoff. Soil probes aren't tremendously accurate either. But, this is better than those 2-prong cheap meters. I like it because I can adjust my soil's starting ph a little with hydrated lime (to raise) or aluminum sulfate (to lower). Not much of either one. Maybe 3-5g per gallon of soil to move it 0.3-0.5 ph.