I would not store it in 4.0
There is a special solution for storage (linked above in my previous comment).
If you are calibrating with 2 points (7 and 4) then make sure to follow the manual. Calibrate 7 first, then without turning the meter off, rinse it and calibrate again in the 4. It will figure out that you are trying to calibrate with 4.
You might have to leave it in the calibration fluid for a little while. When you shake it, it will change some, but it should eventually stabilize again. If the meter takes a long time to stabilize then it probably needs a clean.
If you do a 2 point calibration and then put the meter in 7 buffer solution, it should be close to 7.
If it isn’t it:
might need to be cleaned
might need to be stored in storage solution for a while before you re-calibrate
might need a new sensor.
If you store the meter in storage solution you wont usually have problems with it. I think I’ve cleaned mine twice in 3 years and I haven’t had to replace the probe.
everything’s as you say. i guess it’s working as expected then. only difference is i am dipping in distilled before storing…it has some in there. it never gets dry since i use it almost every day.
Storing it in distilled water can be a problem. I would not leave that in the cap.
As far as I remember the probe actually has a component that stores ions with a positive charge and distilled water will actually take some of those out.
I might be wrong on that, but that’s how I remember it.
I think storage solution is slightly more important than it might seem.
i don’t fill up the cap. i just dip in distilled. the instructions said to not let it get dry or use the long term storage method. so, the little water in it keeps it moist between uses. the instructions for this meter are not like other meters like say blue labs. i let it get dry when i took a month off and that is when the first meter stopped working.
If you run through the different modes whilst in the storage solution you will notice the tds reading will peg out. TDS is a conductivity based measurement and the storage solution is a metal salt (KCl). This does multiple things. It prevents the accumulation of fertilizer salts on the tds electrodes and the loss of ionic material in the ph bulb. As long as there is enough moisture in the storage cap to keep the humidity high enough the water in the bulb doesn’t evaporate you’re good. Distilled water ruins the bulb because it is void of ions which causes them to migrate out.
Unless you’re very careful to use new, unmolested testing solution poured fresh every time you run the risk of drift in the solution. This is the most likely cause of your “inconsistent” readings.
I recently learned this too. NEVER BUY A CHEAP PH METER!!! They break too easy and mine wouldn’t stay calibrated for whatever reason. I had a Milwaukee 600 ph meter. It’s like $30 and it FUCKING SUCKSSSSS. I had it for 3 years until it broke(I never really used it witch I know is bad because my I never got a good harvest) anyways it broke and I bought the same exact one. And nothing but problems sense I bought it. They damn thing wouldn’t calibrate correctly. Finally I got pissed off and bought a Bluelab ph meter. It’s 100% waterproof it’s digital. Auto calibration. It was $130 but it was the best $130 I ever spent. If you are debating on what ph meter to get. DONT GET THE CHEAP ONE
My vivosun $10 ph meter works well enough, i think. I calibrate once or twice a week and it seems ok. I replace it once or twice a year.
I tried using storage solution but that didn’t help. I do rinse in distilled water before and after use.
I read a lot on other forums where the consensus came down to just buy the cheap ones bc they all break over time and you can replace them more frequently for less dough
I agree.
For whatever reason I burned through 2 pens twice as fast as normal when using the storage solution. They would stop being able to calibrate or give readings.
So I stopped and just cap it after dipping in distilled water and haven’t had that issue. I use my pen 1-2 times a week
