Happy New Year to all of you, and nice to meet you. Thank you for stopping by.
I recently acquired an HM Digital PH-200 and the HM DCOM100 meter for measuring TDS/EC and temp. They were bought locally from an older gentleman and he gave with it Advanced Nutrients PH UP and DOWN. These bottles are both almost completely full. I have poked around and the general consensus seems to be that they have an indefinite shelf life. I could be wrong here...
Also Given to me with them were bottles of Calibration fluid (7.0 and 4.01 I believe) General Hydroponics
And lastly an electrode storage solution/calibration fluid with a value of 1500ppm,also General Hydroponics.
My findings have been the calibration fluids can expire quickly, sometimes 6 months or less.
Question is this. How long are the calibration and PH UP/DOWN usually okay for? Just would like some clarification on that.
I put new batteries in the HM PH-200 and went to calibrate it. It would not get anywhere close to 7.0 in the solution I had. It was coming in at 8.5 give or take a little. Cheapest route is to first try new solution $9 (on the way) and if not that- could be the electrode itself? If anyone would like to weigh in on what they know, feel free.
Hope that all was clear, Like I said thank you for checking this out. Blackbriar


I recently acquired an HM Digital PH-200 and the HM DCOM100 meter for measuring TDS/EC and temp. They were bought locally from an older gentleman and he gave with it Advanced Nutrients PH UP and DOWN. These bottles are both almost completely full. I have poked around and the general consensus seems to be that they have an indefinite shelf life. I could be wrong here...
Also Given to me with them were bottles of Calibration fluid (7.0 and 4.01 I believe) General Hydroponics
And lastly an electrode storage solution/calibration fluid with a value of 1500ppm,also General Hydroponics.
My findings have been the calibration fluids can expire quickly, sometimes 6 months or less.
Question is this. How long are the calibration and PH UP/DOWN usually okay for? Just would like some clarification on that.
I put new batteries in the HM PH-200 and went to calibrate it. It would not get anywhere close to 7.0 in the solution I had. It was coming in at 8.5 give or take a little. Cheapest route is to first try new solution $9 (on the way) and if not that- could be the electrode itself? If anyone would like to weigh in on what they know, feel free.
Hope that all was clear, Like I said thank you for checking this out. Blackbriar

Last edited: