Reliability of medium pH testers in Coco coir

[VincenzioVonHook]

Hey guys. I've recently switched to Coco coir, and using my Hanna groline pH probe is far different to potting mix and soil experience. In potting mix and soil, the pH would differ drastically at different levels, different consistencies and different moisture levels, and the reading took a while to stabilise.

I've been measuring the medium pH today in Coco for the first time, and it seems incredibly stable. Too stable to believe. It jumps straight to 6.6, and doesn't differ at all in different locations, which makes me think these probes aren't that reliable in Coco. Am I correct, or off base? Is the wildly differing readings In potting mix and soil due to the large amount of different substances with differing conductivity? Is the stable readings in Coco coir simply because of the uniform makeup of the medium in comparison?

For example, using the cheap backup $20 analogue probe that measure pH and moisture, the Meter will bounce around for a while before stabilising, and if near any form of rocks or bark chips, it won't read at all and wildly vary. Yet In Coco it does the exact same thing as the $100 digital probe. Drops slowly from 7.1 over a few seconds(it's resting point) to 6.7 and just sits there.

This is probably a question where the matching readings shouldn't be questioned, but I can't help but thinking it seems too good to be true lol. Let it rip if I'm clearly overthinking this.

 

[MickFoster]

I think you're over thinking it.
I never check the pH or the ppm's of the coco or the run off.
I just make sure the pH is correct going in and that I always feed to substantial run off.

 

[Southernontariogrower]

Hey guys. I've recently switched to Coco coir, and using my Hanna groline pH probe is far different to potting mix and soil experience. In potting mix and soil, the pH would differ drastically at different levels, different consistencies and different moisture levels, and the reading took a while to stabilise.

I've been measuring the medium pH today in Coco for the first time, and it seems incredibly stable. Too stable to believe. It jumps straight to 6.6, and doesn't differ at all in different locations, which makes me think these probes aren't that reliable in Coco. Am I correct, or off base? Is the wildly differing readings In potting mix and soil due to the large amount of different substances with differing conductivity? Is the stable readings in Coco coir simply because of the uniform makeup of the medium in comparison?

For example, using the cheap backup $20 analogue probe that measure pH and moisture, the Meter will bounce around for a while before stabilising, and if near any form of rocks or bark chips, it won't read at all and wildly vary. Yet In Coco it does the exact same thing as the $100 digital probe. Drops slowly from 7.1 over a few seconds(it's resting point) to 6.7 and just sits there.

This is probably a question where the matching readings shouldn't be questioned, but I can't help but thinking it seems too good to be true lol. Let it rip if I'm clearly overthinking this.

You should callibrate ph meter weekly, ask me why?

 

[VincenzioVonHook]

Cheers @MickFoster ...I've just been paranoid as I planted in this "pH buffered, washed premium hydroponic grade" Coco coir by pinegro.

Transplanted 8 day seedling in peat cubes I to the Coco coir/perlite mix, Mixed up tap water and veg nutes to 400ppm and 6.5, and ran through enough to get a cup of runoff per pot. Thee runoff came out a 6700 and pH 8.4 immediately.

After that I've been super paranoid that there's something suss about this medium...the plants are doing very well though, so I should stop stressing...just never seen ppm up in the 6 thousands.

Had to run through 60L of water to get the runoff to 500ppm. Didn't think to buffer as the medium said not to pre buffer, and the dude at the shop said the ppm comes out nice and low lol.

 

[VincenzioVonHook]

You should callibrate ph meter weekly, ask me why?

Why....I'm going to assume its something crazy.

My sad idea of "calibrating" is testing all three methods (groline pH probe, cheap probe and pH strips) and if they are within a point or two of each other o just average them haha.

I do that with my pH pen as well. .have a bluelab pen and a cheap $20 pen From my aquarium shop down the road. If both of them and the strips all say roughly the same I'm like..yep, she's good.

 

[DCcan]

About 8 pages of pdfs for hanna meters.
Slow response and performance of $20 meter is to be expected compared to a meter designed for a duty cycle.
Biofilms accumulate is the main reason for the performance.
"If coating is a problem in your process, you will notice that while measurements in buffer are accurate, the sensor response time is slow (30 seconds or more). As coating increases, you may notice measurement errors or erratic readings."

Hanna Instruments - Resources Page

From testing guides and best practices to eBooks, webinars, & more, you are bound to learn something new that you can implement in your testing environment! LEARN MORE

www.hannainst.com

How to Reduce Cleaning Requirements for pH Probes | Sensorex

Cleaning pH probes can mean removing them from your process and taking time out of your day. Learn how to spend less time cleaning pH probes.

sensorex.com

 

[Southernontariogrower]

Cheers...I've just been paranoid as I planted in this "pH buffered, washed premium hydroponic grade" Coco coir by pinegro.

Transplanted 8 day seedling in peat cubes I to the Coco coir/perlite mix, Mixed up tap water and veg nutes to 400ppm and 6.5, and ran through enough to get a cup of runoff per pot. Thee runoff came out a 6700 and pH 8.4 immediately.

After that I've been super paranoid that there's something suss about this medium...the plants are doing very well though, so I should stop stressing...just never seen ppm up in the 6 thousands.

Had to run through 60L of water to get the runoff to 500ppm.

Holy shitl never..... wow! Promix hp m all the way, never ph ed it never had a problem. Even feeding 2.4 ph and 3.4 ph, they have done well. Meter was off by 3 ph points. Would never feed that on purpose.

 

[SheeshM]

Cheers...I've just been paranoid as I planted in this "pH buffered, washed premium hydroponic grade" Coco coir by pinegro.

Transplanted 8 day seedling in peat cubes I to the Coco coir/perlite mix, Mixed up tap water and veg nutes to 400ppm and 6.5, and ran through enough to get a cup of runoff per pot. Thee runoff came out a 6700 and pH 8.4 immediately.

After that I've been super paranoid that there's something suss about this medium...the plants are doing very well though, so I should stop stressing...just never seen ppm up in the 6 thousands.

Had to run through 60L of water to get the runoff to 500ppm. Didn't think to buffer as the medium said not to pre buffer, and the dude at the shop said the ppm comes out nice and low lol.

New coco with a high ppm could be salt in the coco. It says it's washed but it doesn't hurt to rinse it, just so you know the ppm is reasonable to start.

 

[VincenzioVonHook]

About 8 pages of pdfs for hanna meters.
Slow response and performance of $20 meter is to be expected compared to a meter designed for a duty cycle.
Biofilms accumulate is the main reason for the performance.

Hanna Instruments - Resources Page

From testing guides and best practices to eBooks, webinars, & more, you are bound to learn something new that you can implement in your testing environment! LEARN MORE

www.hannainst.com

How to Reduce Cleaning Requirements for pH Probes | Sensorex

Cleaning pH probes can mean removing them from your process and taking time out of your day. Learn how to spend less time cleaning pH probes.

sensorex.com

Cheers....my I just took them out the box, got some distilled water and put a 6.86 sachet in there...it said 6.9 so I left it..

Only use the cheap Meters as a back up to my groline and bluelab gear, and my excuse to not calibrate or read manuals was simply "hey, all three methods test the same so it must be right". I do have a habit of skimming over certain things.

Ill have a read through.

 

[VincenzioVonHook]

New coco with a high ppm could be salt in the coco. It says it's washed but it doesn't hurt to rinse it, just so you know the ppm is reasonable to start.

I should have listened to everyone here in the first place tbh. There's adequate info about washing Coco here, but I fell for the "premium facilities that process without salt water, guaranteed low salt residue" lines on their product.

 

[VincenzioVonHook]

Btw, that was 60L PER POT I had to run through to get it down to 500ppm lol. .180L of water.

 

[DCcan]

Cheers....my I just took them out the box, got some distilled water and put a 6.86 sachet in there...it said 6.9 so I left it..

Only use the cheap Meters as a back up to my groline and bluelab gear, and my excuse to not calibrate or read manuals was simply "hey, all three methods test the same so it must be right". I do have a habit of skimming over certain things.

Ill have a read through.

Just store the cheap ones dry, soak them in water 20 min before turning on or the electrodes will be damaged.
Day to day use, use: KCl storage solution>a 1:1 mixture of pH 4 buffer and 3..4 M KCl solution,> 4.0 calibration solution,>or water for PH meter.
Distilled > tap water for EC meter.

 

[VincenzioVonHook]

Just store them dry, soak them in water 20 min before turning on or the electrodes will be damaged.

Lol. I've probably destroyed them then. My whole approach has been to clean them with distilled water when I'm done, dry them in warm air and then upon re-use, I just put it in the solution for a few seconds before I turn it on. I should probably do my research when I spend decent money on gear.

 

[DCcan]

They will probably be fine, just degrades the electrodes, makes it less responsive, hopefully.
More....

Storage, Cleaning & reconditioning pH electrodes and EC Electrodes

Just some basics put together for keeping everyone green. Note that Ph meters and EC meters should be stored in different liquids, and why. Keep Your pH Electrode Hydrated: If your electrode is dry, rehydrate the sensing tip by soaking the bulb and junction in an electrode storage solution for...

www.rollitup.org

 

[Southernontariogrower]

lll never go without drops again, used for decades will use again, not so happy with meters atm. I will definetly callibrate weekly if l buy a new one. IF!

 

[DCcan]

Went from cheap meters (did all the mistakes) to the tedious but accurate drops+ strips, to waterproof meters, then wrote it all down to remember WTF to do.

Just keep them wet in anything, rinse them off is 80% of keeping them accurate.
Using the correct storage fluid and routine cleaning gets an accurate reading in a few seconds, the electrode is really responsive and last for much longer.

After filling infinite 5 gal buckets mixing nutes, you get a feel for when it needs calibration.
Needs a good cleaning after sticking it in something weird ( thicker foliar sprays, oils ), then calibration.

 

[Bukvičák]

Bluelab measures just fine mix as well as coco, untill coco get obviously bounded, than I can observe numbers like 4,0 when I try to push the probe whole down inside pot. Probably meshed some roots, so since then I never measured its pH again during the grow. But you can measure whatever you want, also inside your ass if you want to know that and youll get reliable results I think...

 

[twentyeight.threefive]

the dude at the shop said the ppm comes out nice and low lol.

 

[MickFoster]

lll never go without drops again, used for decades will use again, not so happy with meters atm. I will definetly callibrate weekly if l buy a new one. IF!

Been using the drops for decades........they're never wrong.

 

[1212ham]

Went from cheap meters (did all the mistakes) to the tedious but accurate drops+ strips, to waterproof meters, then wrote it all down to remember WTF to do.

Just keep them wet in anything,

Never store in RO or distilled water!