Did I Break my Ph Meter??

troutfarm

Well-Known Member
I bought an inexpensive ph meter for my last grow and it worked amazing! I calibrated it when I got it and did random comparisons to the drops throughout the grow and it seemed to give very accurate results. I used it every few days during the grow.

I'm just starting a new grow now, after an 8-month hiatus, and the ph meter was stored dry, with the cover on for that period. My understanding is there is a storage fluid that should be used, but I didn't use it. Now, when I tried to test it I'm getting wacky results. Distilled Water, which from what I understand should be roughly 7.0 starts reading 7 on the meter, then I swish it around and get 6.7, then 6.2, then 5.8.. all the way down to sub 5's. I didn't re-calibrate it since I blew the dust off, but my long drawn out question is, did I ruin it by storing it without fluid to keep the sensor working? Should I just re-calibrate or is it too late? Thoughts? (pic shown is when I first got it and compared to drops).

broken_ph.jpg
 

pulpoinspace

Well-Known Member
distilled water reacts with co2 in the air and becomes acidic
dont test it on distilled water test it on a buffered solution

no harm to recalibrate it if it's off
 
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hotrodharley

Well-Known Member
The probe element might be toast. Consider cheap litmus paper. More than adequate for our needs. Store dry. Never needs calibration.
 

GBAUTO

Well-Known Member
You can try to rehydrate the test bulb by immersing the probe overnight in tap water. That may help to stabilize the readings and allow you to recalibrate...or you could spend $15 and either buy a new 'inexpensive' probe(that's what I do yearly) or buy some test paper(it never wears out).
 

troutfarm

Well-Known Member
You can try to rehydrate the test bulb by immersing the probe overnight in tap water. That may help to stabilize the readings and allow you to recalibrate...or you could spend $15 and either buy a new 'inexpensive' probe(that's what I do yearly) or buy some test paper(it never wears out).
I do enjoy getting an actual number (as long as it's accurate of course) so I want to stay digital. I think I'll take some of the advice and toss this one, replace with another inexpensive one, but order the storage fluid as well this time. Thanks everyone!
 

troutfarm

Well-Known Member
Another quick question... I also have an inexpensive ppm meter that was also stored dry with the cap on. It seems to be working just fine. Should I be storing that with storage fluid too, or is that just for ph meters?
 

Kingrow1

Well-Known Member
You can try to rehydrate the test bulb by immersing the probe overnight in tap water. That may help to stabilize the readings and allow you to recalibrate...or you could spend $15 and either buy a new 'inexpensive' probe(that's what I do yearly) or buy some test paper(it never wears out).
You cannot rehydrate a probe with water, you need the right ionic solution i.e. Kcl.

It is advised to 24hour kcl soak every month to keep things sweet.
 

GBAUTO

Well-Known Member
Just suggesting what every one of the instructions that have come with the meters I've used.
 

Kingrow1

Well-Known Member
Just suggesting what every one of the instructions that have come with the meters I've used.
Yep its why the cheap ones give out real quick, youll extend their life by performing a simple google search on maintenance and rehydration, just click the hannah or bluelab or siemens link even one of the othe hundred sites :-)
 

troutfarm

Well-Known Member
I'm confused and need more help please! I bought a replacement inexpensive ph meter, the same one I had before I let the old probe dry out. As can be seen in the picture at the top of this thread, after calibration my old meter seemed to match perfectly with the drops (Every few weeks I'd compare the two).

I calibrated this new probe and compared it to the drops and they don't seem to match at all. The probe consistently offers a lower value than drops. In the pics posted the meter reads 5.82 but the drops seem to be around 6.5 to me (I put in about 7 drops to get a deep color). I went through the calibration process again with similar results (using all 3 packets both times).

I have two questions. Does distilled water go bad? I'm using the original jug I bought 8 months ago. It was stored sealed and in the basement on a cement floor but not in a dark area. Also, I read somewhere that the drops can be inaccurate... but most don't seem to hold this position. These are the same drops I used to compare last time so they are about 8 months old as well. Is it safe to assume that the drops are giving the more accurate result here?

I'm about to contact the Amazon seller about getting a replacement ph meter but wanted to consult the experts here to ensure I'm not doing something wrong on my end.

ph_meter_nov2018.jpg
ph_drops_nov2018.jpg
 

shushubandora

Well-Known Member
Once i got used to my setting I hardly measure pH.
I use tap water and know 2 mil of phosphoric acid in 10 liter is enough to get me to pH 6.3. And it's doesn't change.
pH is logarithmic scale. pH 5 is 10x stronger then pH 6 and 100x stronger than pH 7.
There is no reason to go below 6, I tried once and I got the dark color on leaves. I didn't saw an article or reaserch showing its better, keep in mind water evaporate while acid much less. To avoid over acid and salts I use only tap water once every 2 weeks. (in my area it's pH 7.5).
pH setting is probably the last thing I worry about, temp in the winter can be a pain.
 

troutfarm

Well-Known Member
Magic! I retested everything tonight and now the ph meter is matching the drops. I can only assume that a brand new meter may have dried out the probe a bit on its own and since I dunked it in a bunch of liquid yesterday and capped it, assuming it wasn't working, the water re-moisturized and is working again? I have no idea, but I'll re-calibrate and test again to be safe but it seems all is good now. Weird.
 

Kingrow1

Well-Known Member
Magic! I retested everything tonight and now the ph meter is matching the drops. I can only assume that a brand new meter may have dried out the probe a bit on its own and since I dunked it in a bunch of liquid yesterday and capped it, assuming it wasn't working, the water re-moisturized and is working again? I have no idea, but I'll re-calibrate and test again to be safe but it seems all is good now. Weird.
Seems to me that you need to get some practice of how to use, store and hydrate a ph meter, all of that is wrong and its hard for the guys on Amazon to sell more advanced equipment if you keep returning it through lack of knowing how to work it.

Im not here to explain, simply google hannah or siemns basic ph meter operation info :-)
 

troutfarm

Well-Known Member
Seems to me that you need to get some practice of how to use, store and hydrate a ph meter, all of that is wrong and its hard for the guys on Amazon to sell more advanced equipment if you keep returning it through lack of knowing how to work it.

Im not here to explain, simply google hannah or siemns basic ph meter operation info :-)
Thanks for the help.
 
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