I bought 3 of the very cheapest ones I could find on E-payd (for for some rich guy’s house).
They all registered the same thing and did match pretty well with a paper test.
I gave two away, but they were less than $5. Made in China.
Now I know just how bad my PH problem is, and I correct on every watering or feeding.
Holding at just above 6 
I have this one (COMBO Meter) and i am happy to have it… I think it’s pretty precise.
I think I have a pH meter still. Not using it in my ROLS or no-till, but do pH my cloner.
I ended up going with this one https://www.amazon.com/gp/product/B01ENFOIQE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Replaceable probe and decent price. Good reviews on Amazon.
I would have probably gone with the bluelab pen for a little more money but I couldn’t get it through Prime and I wanted it fast.
interesting i didn’t know it had 4 types of probes. one for flat surfaces (skin, microsolutions/saliva) one for food like cheeses, sushi, etc. lol who is checking the PH or PPM of their sushi!
I have good experience with Milwaukee Smart pH Monitor … In photo here in my growroom
Bluelabs are great, but slightly more expensive…
Hola OG brothers and sisters. Does anyone have a pH meter that the are pleased with? My $15 one made it through one grow and won’t calibrate anymore. Gotta order one. Anybody? Thanks all. 
Bluelabs PH pen are pretty decent.
https://www.getbluelab.com/shop/By+Category/Pens/Bluelab+pH+Pen.html
You can find them cheaper than the OEM price.
Most important thing with the pens is proper storage in storage solution. Keep them wet.
Was it one that has to be stored insolution? If left dry that will fuck em up from what I’v heard but then again those are the ones of upwards of a100$ I think!
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.
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.
Yes, you’d 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. You’d make certain that the sponge remains saturated with the storage solution occasionally and you’ll 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.
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.
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.
Many thanks @Northern_Loki. I have not been maintaining them correctly. This pearl goes directly into oleskool’s Big Red Book of Aquired Knowledge. 
I go through pH pens like crazy. I have found the cheap Chinese ones are the best for the price.
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.
That will teach you to clean and calibrate before every use hahaha as if i do NOT.
