Ph/EC tester reading

Grow Equipment
1

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???

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Follow the manufacturer’s directions for calibration of the meter. They’re not all built the same.

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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.

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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

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Yes, you need to do 2 point calibration. If the manufacturer has specific recommendations on solutions, attempt to find recommended solution.

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6

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.

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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 :metal:

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Yeah, my Apera ph20 also says 7.0 first.

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9

Mine does say you can go 7 then 10. But 4 seems to be the most popular and available. Either way, 2 point ck

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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

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11

Exactly :100: Apera also talks about 3 point calibration with 10 solution, but I don’t see the point :slightly_smiling_face::+1:

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12

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.

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13

I would use the the liquid solution not the packets

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Thanks again for the help as I stumble on. Stumbling with a grin.

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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.