You leave in the solution all the time? @Northern_Loki? 
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Was it one that has to be stored insolution? If left dry that will fuck em up from what Iāv heard but then again those are the ones of upwards of a100$ I think!
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there is a sponge in the cap i keep wet with ph 7 cal solution or a ph storage solution i am guessing its de-ionized water. If yours does not have a sponge you can add your own.
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I just buy the 10 dollar ones every 3 to 18 months and keep the bulb humid by putting the cap on straight away.
It always pays to have a spare on hand.
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Yes, youād leave it in a storage solution when not in use.
Sealed glass bulb PH pens need to be stored in a solution that contains potassium chloride (KCL) that is buffered at either a PH of 4 or 7. Pens usually come with a starter quantity of storage solution but it can be easily found on-line or at most hydro shops. If you look closely, these pens will have a glass bulb similar to:
This storage solution has two purposes, it keeps the solution within the glass bulb from drying out and it ensures the solution that is in the glass bulb of the probe has a proper concentration of ions that are used when making a PH measurement (keeps it conditioned). You do not want to store a sealed glass bulb probe in RO or deionized water as it will leach out the ions from the glass bulb solution over time. You also do not want to leave the glass bulb to dry out. In a pinch, regular tap water can be used until you are able to buy or make some storage solution. It is not always easy to resurrect a PH probe that has been left to dry or has the ions leached out of solution. Your best bet is to get in the habit of placing it into a storage solution once you are done using it. This is true of cheap or expensive probes. Some probes can be refilled but those are rare outside of a laboratory.
The Bluelabs pens have a cap with a sponge as argo945 mentioned. Youād make certain that the sponge remains saturated with the storage solution occasionally and youāll be good to go.
There are a variety of discussions around regarding the accuracy of cheap vs more expensive probes and I do not have much to say other that there are probably some inexpensive models that will maintain acceptable accuracy over time. In particular, if you calibrate them regularly.
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I just got this Myron pen on Friday and so far it seems to be pretty good. I had a Hanna for years until it took a crapper on me back a week or so ago. I was searching around to a lot of mixed reviews and then I found this pen and this was the best deal on it.
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Yes sir. But, avoid storing them in deionized, RO, or purified water. Regular tap water will do for a short period when in a pinch.
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Many thanks @Northern_Loki. I have not been maintaining them correctly. This pearl goes directly into oleskoolās Big Red Book of Aquired Knowledge. 
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I go through pH pens like crazy. I have found the cheap Chinese ones are the best for the price.
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Stupid things always go-wonky JUST when I need them.
I switched over to pH drops/strips exclusively, a few months ago.
Last time one broke on me, it was reading 6.2 for 7.5pH water. Plants were unhappy.
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That will teach you to clean and calibrate before every use hahaha as if i do NOT.
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Ya, really. Another reason to abandon them. Most days I donāt have the spare 15 minutes.
for the record alsoā¦I actually DID clean and calibrateā¦ it was still reading off in my solution. Iām not buying another one ever.
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Blue labs constant read out, probes in solution, PH and EC, connected via sms equipment to an old nokia 3310, cant go wrong, or you get a warning when things do hahahha by a simple sms txt OLDSKOOL
For every day use mixing up vats of 100 litres or less I use the cheap pens, for vats containing more than 100 litres I connect constant read out probes as the vats top up them selves up via ball cocks and auto dose.
I find if you mix enough nutes you know when theres is something wrong just by the numbers not reading what you expected from what you have put in. I had it the other week, I guess the water utility company changed reservoirs supply, I had a drop of ph from 7.2 to 6.2 for the tap water over night.
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There was a discussion a little while ago about different PH pens. Expensive vs cheap, etcā¦
take a look at the thread starting at post #4978 :
https://overgrow.com/t/chat-room-lets-chat-speech-balloon/2745/4978?u=northern_loki
I have a BlueLabs pen and a scientific grade PH probe/meter. Almost never need to use the scientific unit, the BlueLabs pen has served me well so far.
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I was recommended a blue labs from a shop in town but never actually looked into them @Northern_Loki Iāll start readin right now. Thanks again. 
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If you look around a bit, you might be able to find one on-sale. They are not the cheapest option but they seem to have a good reputation.
At one point they sold a kit that included both an EC and PH pen that was significantly cheaper than buying them individually.
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Iāve bought three of the cheap ones. Could have bought a Bluelab instead. I rarely measure pH in organics, but I have drops for when something seems off.
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Iāve seen them on amazon but not sure because the price is like half the price of the link you sent in that other post
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That link was direct from BlueLabs at the suggested retail price, which is almost always higher than the street price. Iām sure there are better deals that could be had through an authorized re-seller.
But, yeah, at half priced Iād spend a little time to research the sellers reputation it to avoid the possibility of APAC counterfeits. Not that is the case, but Iāve been there/done that.
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