I have a Hanna Checker PH meter and in the 7.0 and 4.01 cal. solutions the meter reads what it's supposed to read, but once I put it in the water from my res. it reads ~6.15 no matter how much ph down I use. Did it die on me? Once I got to my usual dose of down I stopped adding because I didn't want to crash the PH too low. I just ordered a new meter anyways because I don't feel comfy with this one any more.(not the first prob.) Cost $20, guess you get what you pay for but I thought Hanna was a trusted name.
All you homegrown scientists, and no one knows anything about meters? Give a brother some help. Pretty please with kief on top!
If it responds to the solutions it is probably working. Are you mixing the pH down well in the water before testing? Could you have some bad pH down?
I don't know? I just vegged out two males with all the same stuff fine until yesterday. The meters been screwy since I got it. I have to recalibrate it every 3-4 tests. It just drifts. now this. I just don't trust it anymore but don't want to throw it away if it's a probe issue.
Ive found the soil tests were always way more accurate. The Rapitest Soil Test Kit is great... check your NPK levels and your PH.[ame=http://www.amazon.com/Luster-Leaf-1601-Rapitest-Soil/dp/B0000DI845/ref=sr_1_1?ie=UTF8&qid=1289497443&sr=8-1]Amazon.com: Luster Leaf 1601 Rapitest Soil Test Kit: Patio, Lawn & Garden: Reviews, Prices & more[/ame] Why are you trying to lower your PH below 6.15? Ive always heard to stay in the 6's. Second of all if you would rather have a tester you can just shove in the dirt (potentially breaking lots of roots) I read rapitest was the best brand. I have their 3 in 1 meter light, moisture, and pH. Honestly i only use it for the moisture portion and even thats not incredibly accurate. The 4 in 1 is the one i read was decent, [ame=http://www.amazon.com/Luster-Leaf-1818-Rapitest-Tester/dp/B000RUI9QK]Amazon.com: Luster Leaf 1818 Rapitest Mini 4-in-1 Soil Tester: Patio, Lawn & Garden: Reviews, Prices & more[/ame] it can do light, moisture, PH, and apparently you can check your nutrient levels. I havent tried it out but have read on some forums of ppl doing tests with it vs the soil test and it was pretty close to accurate. Another thing you should be doing is testing multiple places in your soil (with either test) because if your just measuring one little spot your not going to get an accurate read on ALL your soil. Good Luck!