Cheap ph meter

Discussion in 'Growing Marijuana Indoors' started by Popcorn, May 24, 2019.

  1. Hey I just got the cheap yellow ph meter can I calibrate it with 7.0 solution instead of the 6.86?
     
  2. Sure; that's what I always do.
     
  3. yuppers, but u should also be using pH 4.0. Calibration exist between 2 points, A and B. They never reach A or B (4.0 or 7.0) so you just get it as close as you can.
    For example, I calibrate my cheapo yellow meter to 4.15 (in 4.0 solution) and 6.85 (in 7.0 solution); there is a difference of 0.15 between the values.
    If I did not use 4.0 and just used 7.0, then I would calibrate to 7.0=7.0, but the reality would be that at lower pH, it would be (assuming) 4.30.
     
  4. Also with my hanna I just had to stick it straight in solution. This meter is telling me to mix with 250 ml distilled but no amount for solution.
     
  5. I ordered one of those but haven’t got it yet. The opinions I’ve read here are pretty negative on them?
     
  6. Many times it depends on how one treats them. I have a tendency to treat my meters like fine china lol. I clean them on a regular basis, always have the tips submerged in R.O. water when I store them in a small glass, and I calibrate them weekly. I currently have a $35 Hanna, which has lasted me 2 years and still going strong. However, before that I ordered one of those yellow, cheap $10 pH meter from Amazon. I knew it was cheap, but I was on a budget. Best $10 I've ever spent on a cheap meter lol. It lasted me a good 3 years before it totally gave its last breath. Not saying all come perfect. Sometimes it's a crap shot. You get what you pay for. Just saying that if you happen to get one that works, proper maintenance can make it last longer than you think. So don't lose hope lol.
     
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  7. i try to be clean with it, but i got too many things on the go and am a sloppy boy. i sometimes store it in 3m KCl, but usually let it sit in the black cover after use. I've had it over a year. I have a brand new back up, I compared it to the other one, it is farther out of range than the one i;m using, so i imagine its a hit'n'miss thing too.
    I suggest to always buy two cheapo meters and always replace the one that dies.
     
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  8. So got an answer on mixing it with water?
     
  9. Great idea about buying two. They're cheap as it is (if you buy the yellow ones), so why not two (smacks self in back of head lol). Funny (but true) story I had a couple of years ago concerning always having backups in a journal I kept while growing a White Widow. I'll just copy and paste it below:

    "I woke up to find the pH at 8.0. I double checked and it was at 13.6. Very odd. I went to calibrate my pH meter, but the numbers were going all over the place and wouldn’t let me calibrate. I changed the batteries with same results. I finally came to the conclusion that after a few good years of service, my pH meter has taken its last breath. It was a good, little, cheap meter too though. Good thing I still had my pH strips kit as a backup. I checked the pH twice and it was at around 6.5, so I left it alone. Imagine if I had panicked and just went ahead and added pH Down to the nutes without double checking the meter? My pH would’ve been in the 3’s or 4’s by now. Always check/calibrate your meters people." lol

    Honestly, I never read of doing that with any of my meter. I just use the 7.0 and dip that sucker in there.
     
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  10. that's what taught me to always check for.

    @Popcorn I did not understand the comment about water. Do you mean you have a dry calibration powder that you need to add water to first? If so, follow their instructions and use RO. But if you mean to add water to the nutrient solution before you measure its pH, no, that's unheard of. If you are adding RO, there shouldn't really be much an effect on the pH anyhow.
     
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  11. Oh duh, I had not thought about dry ph buffer. The only thing I ever used is the hanna/bluemap buffers that come in a small package with liquid, that's to all going to ph and feed here when I get up in a few hours
     

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