The tale of two ph pens

[Going2fast]

I've been having a few issues with a couple plants and although I don't think this is the direct cause I thought I'd share this with yuns. So I decided to check the calibration on my ph pen. It's a cheap Amazon special. Allprettyall. I know right. But I've kept up with calibration and all since I got it so everything is good right? I decided to bring our rather expensive Apera from work as a litmus and calibrate both at the same time. This will be broken up into a few posts so the pics jive with the narrative. Drew water for the plants and let it set for a day at room temp as usual then did the test pre calibration. Now this is straight well water. Take note the extreme swings in pH on the cheap pen.

[Going2fast]

Then I dosed it with pH up to what I believed was 6.5. all tests were a full 4 minute soak.

[Going2fast]

Next I did a full three point calibration to both with fresh unsealed test solutions of 7.0, 4.0 and 10.1. rechecked in 4.0 afterwards.

[Going2fast]

And back into the ph adjusted water. First soak for 4 minutes. The Apera was stabilized in about 30 seconds. The other was still slooooowly climbing after 4 minutes.

[Going2fast]

Let's wait 10 minutes and test again.

[Going2fast]

And one more time.

[Going2fast]

Conclusion....those cheap pens are trash. How can it read accurate in test solution only to be soo far off on water? Yeah that sumbitch is going straight in the trash.

[changeofpace2014]

I have two Hannah ph meters both in the TRASH...Bought a 3rd one lol...Had same issue with them, and was kind of in a panic, the replacement ph meter came but the box was opened and it was broke...Further delay to get a working meter...When I was waiting on new ph meter i was setting my solution ph low, but with in range...I guess I got lucky or it was just GRACE the girls did not develop any major issues, mind you buy that time I was already adding the extra enzyme additive. There is no substitute for Quality Tools what ever they may be...

[changeofpace2014]

Thought I should add this..Just cleaned my hannah ec meter with cleaning solution and proceeded to cal it..Battery at 80% but meter will not cal; it just through an err..Solution was to replace battery and it accepted the cal with out err.. Check Your Battery if your meter will not cal.. IMO Hannah is a good meter one of the top 3 but the cheapest of the three..Blue, Apera would be a much better option, I think they are built for real world gardening..bumps, bangs and drops..Hannah appears to be really fragile, even when careful.

[3Berries]

I went through the same thing over the years. Last bunch of rejects were PPM meters I sent back. I ordered two of them and they would not agree with each other. Water probes is another. Bought three and two read the same.

[Sixwinds]

Ha, I did the same - used a crappy Amazon pen for the first year and had ton's of issues. Then I bought that exact Apera pen and never looked back.

[Blowdout2269]

I've done a similar test with a couple old pens also, and alongside some paper. I found it odd to be off after calibration aswell. I recently broke down and bought myself a BlueLabs pH meter. It is amazing. I love the little "check calibration" reminder after so many uses. It never really drifts much at all. They're only about $80 these days. A great investment indeed!

[RetiredGuy]

Thanks for posting, gives me confidence in my Apera!

[Smallgrow]

Plus one ,
I had the same experience when I started . After two rough grows with the Amazon pen I bought a blue labs pen and tested both in a similar fashion with similar results.the cheap pens are not reliable.
thanks for showing everyone so clearly with your demo Going2fast
For those using PH and PPM meters sometimes the two pack can be the best deal. It’s defiantly worth it if your serious about growing weed easy .

[DW2]

Howdy Going2fast, that is why I use the litmus test strips. The test strips are accurate enough, around 0.25, (the resolution of most pens, 0.01, is not needed for growing) and return a repeatable result. The test strips require no calibration, battery, or special storage, other than keeping them out of direct or bright light and dry. I use the LabRat brand that has a narrow range of 4.5 to 9.5 pH.
Good luck in your growing.

[Ckbrew]

pH pens suck. The up keep and storage requirements make them a PITA for even the most OCD lab rat. How many times have I seen someone with plant issues that are traced to pH being off, and ultimately found that the pH pen was inaccurate.

I, an OCD lab rat, use these. Much easier, reliable, and all things considered, more accurate.

https://www.amazon.com/Hydrion-Chart-Dispenser-5-5-8-0-Range/dp/B00QLBVP74/ref=sr_1_36?crid=2SQNNGF3K0TSF&keywords=ph+paper+5.5-8.0&qid=1674945379&sprefix=ph+paper%2Caps%2C119&sr=8-36

[Blowdout2269]

I use the same strips as a back up or when I'm lazy, lol.
I also use the ones that go down to 3.0 for my canning.

[Bluey]

I started out with the cheap one on the left. I am on tank water and it drifted all over the place....it then started giving me different readings, it's a POS! I then dropped it into the tank..good bye POS!
I then bought the same Apera as you Going2fast and it's made a world of difference.
I had a nute deficiency in veg and I upped the pH0.2, problem solved..couldn't do that without a good pen.
Lemon juice for -
Potassium Carbonate for +
Tank water varies from 5.5 up to 6.2 depending on stuff.
i calibrate every few weeks and it doesnt drift more than about 0.03pH
good article Going2fast