Second time grower. First batch sucked. From spider mites to Ph problems. Grew pretty bud, but all dud. Starting CLEAN this time. Bought a HM 300 tester last year. Calibrated with 7.0 solution. Needs to be done again. I have 4.0 solution. Can I use that or should I get the same 7.0? Didn’t seem to give same readings this year. My tap water was 6.8 last year. Reading 7.7+ this year. I don’t think my Ph should change that much but???
Follow the manufacturer’s directions for calibration of the meter. They’re not all built the same.
I recommend to do a 2 point calibration on your ph meter with 4 an 7 ph Solution you will have a more accurate reading.
A bit technically challenged but I will research 2 point calibration and give it a go. I have the 4.0 guess I need some 7.0 as well
Yes, you need to do 2 point calibration. If the manufacturer has specific recommendations on solutions, attempt to find recommended solution.
Thanks…have the 4.0 solution that came with the HM 300. Used the 7.0 during original set up. One article suggests starting the 2 step calibration with 7.0 then calibrating with 4.0 or 10.0. Which is best for cannabis in Coco.
My blue lab pen says use 7.0 then 4.0. I don’t think the plants care how you get to calibration as long as you get there
Yeah, my Apera ph20 also says 7.0 first.
Mine does say you can go 7 then 10. But 4 seems to be the most popular and available. Either way, 2 point ck
For all intensive plant growing purposes, 7 and 4 maybe better. Our ranges fall in between there so its what really matters.
Now if you can do the 10? Why not. But I wouldnt order it just to say I did
Exactly Apera also talks about 3 point calibration with 10 solution, but I don’t see the point
For cannabis we just need to be calibrated between 4 and 7. (Check your user manual for which needs to be calibrated first. It’s usually 7 then 4) That covers the ph ranges we’re looking for.
I would use the the liquid solution not the packets
Thanks again for the help as I stumble on. Stumbling with a grin.
Check for directions on your specific tester. Depending on how the span and range adjustments are programmed it could make a substantial difference when and how you use calibration fluid.