PH meter warning!

Hi guys

Bit of a story . . . . . . . . .

Ive just started getting a few plants showing lighter green leaves than normal.

I follow a very strict regime and knew everything was within tolerances as they should be, so I went hunting the forum to see if I could find anything and I couldnt, so I was left with no alternative but to go back to basics and go through everything I do with a fine tooth comb, zilch, everything was right.

But I KNEW something was wrong, my plants were telling me something was wrong and needed help, I even checked online if feeds with NPK levels deteriorate with time and contacted the manufacturers and was told its possible after 5 years of being open that the % could change.

As I knew the feeds im using are new, it wasnt that, but still knew something was causing me NPK issues .... off I went hunting again.

I kept getting back to the same conclusion, it was a PH problem causing a lock out, but this couldnt be, I ALWAYS check PH after I nute my watering can to make sure its within tolerance and also check the run off PH, absolutely fine and as should be.

I seemed to be banging my head against a wall and gaining no answers.

So I thought to myself.. Hippy .. you know everything is correct yet you know something is still wrong, I stood in my greenhouse and in my mind went through my routine and in the greenhouse I realised something, I was relying on 1 item of technology, the PH meter, I checked it out and sure enough it was working fine (its a PH meter that checks soil PH, light luminosity and liquid PH)

The PH meter was telling me the water after the nutes had been added was 7.8 so I was altering the PH lower to 6.5, a difference of 1.3 on the PH scale.

Here is where suddenly like a brick hitting my head I knew I had to do something...

I had to check the PH meter is correct.

So I ordered a digital PH meter off ebay for £16.

When it arrived the instructions said I need a PH 7 buffer to calibrate it (not told this by the ebay seller, typical) so ordered a PH7 buffer and calibrated the digital Ph tester.

I went to my greenhouse and followed my exact routine using the cheap PH tester which uses 2 probes that measure the electrical resistance of the liquid giving a PH reading and this is where the I found my problem.

I was being told after nutes added the PH was roughly 7.8, where in fact it was measuring 6.3, so I was altering the 7.8 reading down to 6.5 using the cheap PH tester, what I was actually doing was lowering the real reading of 6.3 down to 5.0 PH :shocked: :shocked: :shocked: :shocked: :shocked:

The 2 prong tester was giving me a fake reading.

Upon researching the double prong multi testers I found time and time and time again warnings against them because they are notoriously innacurate!

What I had was Mg deficiency (Magnesium gets locked out of soil growing at ph levels of 2.0-6.4)


Do not do what I did, I cut a corner and tried saving £10,

You get what you pay for in this world.

YOU HAVE BEEN WARNED.

eace:

The PH recordist is 5 months old, same as the beer baby, I made a mistake, I did wrong, I trusted something that told me untruth.

It was a silly mistake, all my knowledge trusted into 1 componant.

We all live and learn.

ya i had one similar to that that i figured wasn't right so i replaced it. good looking out hippy

hey hippy could you clarify which one you found to be defective from the picture lineup i have the larger one in the first pic??was this the bad one

sorry hippy i looked closer and it hit me the larger one is the new one...i have had mine for all of my first grow from day one no problems yet

got linked here from your post in another thread HIE..thought i'd give a little :bump:

very important, and often overlooked.

myself it was the last thing i checked when i was having problems.. sure as heck the calibration was off, and my 6.5 PH was actually 7.4

even with a quality meter, it's good to calibrate it once in a while (i check mine every month now, just to be sure.. i use an old school hanna which has the calibration dials on the front that can easily be bump by acident)

New growers overlook the importance of PH.

99% of problems are interlinked somewhere with a PH issue.

Soil drops or strips or probes are all substandard and not accurate enough.

It has to be digital.

And calibrated correctly

eace:

Hell yeah that is so true !

I had that same cheap piece of crap meter too. I had the same problem. my water was reading very high. I bought a Hanna digital and MAN what a difference. Throw that cheap crap away.

should recalibrate once a month anyway...
but that two prong gizmo is strictly for soils. not liquids.
i have a couple different two prong thingies...
they read pretty close to what i was reading digitally in the run off.(soil grow)
but def not for hydro. you would do better with strips.
stick with the digi pen, only way to go. :cool2:

Just went to the hydro store and had them check my calibration..it was off a little, but it's good to have one less thing to check when things go wrong!

good call Hippy!

daddyo said:

should recalibrate once a month anyway...
but that two prong gizmo is strictly for soils. not liquids.
i have a couple different two prong thingies...
they read pretty close to what i was reading digitally in the run off.(soil grow)
but def not for hydro. you would do better with strips.
stick with the digi pen, only way to go. :cool2:

Click to expand...

That's exactly what I was going to add...I hve one of those 2 prong meters but only used it for moisture checking...the ph meter part is not for liquids...it only checks the soil ph and it does that badly....I am pretty sure on the back of the packaging in small print it said for soil only not liquids...
I love my Milwaukee...