Question about ph meters, need some quick advice!!!

[GrimloxK]

Hey buds, hope everyone is having a blessed weekend.

So I just got a cheapo ph meter and I just wanted to know how you guy/gals calibrate your ph meter...

it came with a 6.86 and a 4.0 solution. Should I set the 6.86 first then calibrate the 4.0?

are there any liquids that I can reference to see if my calibration is correct?

Also how do you guys store your ph meters. I've read some HAVE to immerse their ph probe in a solution always...and others just let it dry out.

wtf do i do?

mines has a glass globe with a slim piece of straight metal inside...i'm guessing this is the electrode.

all help is appreciated!

 

[Alien Abductee]

Always do the 7 (6.86) fluid first, best to check the manual, if it has one, but that is the general procedure. There isnt much you can test your meter on with any accuracy, other thant he buffer solutions. If they match, then your on.

You should invest in some storage solution long term, If I have no solution, i use any water that is under 7.00 ph for temporary storage.

I use my meter 4-5 times a day at least, so long term storage isn't really an issue for me.

If your going to store it long term, I heard drying it out is best, then rehydrating it by
soaking in 7.00 neutral water for a bit.

 

[GrimloxK]

thanks alien.

So I just did a recalibration with the 6.86 first then the 4.0.

I tested the store bought purified water and to my surprise it came out 5.5

I tested my tap water and it came out 7.0.

does this sound fishy? I mean purified water should be neutral right?

 

[Alien Abductee]

Nope, my tap water is 8.0 sometimes, 6.0 other times. the purified water i buy is around 6.0. The only accurate source is the testing solutions, so if you tested them, then put the meter in the 6.86 solution and it tested correctly, then that is the ph within the range of accuracy the meter states.. usually +- .1.

With time, I learned to tell when the meter was off, because I have an expected ph. Meaning.. when I wake up I expect the ph to be X, if it isn't ill grab the calibration fluid and test, sometimes its on, sometimes its off, but safe to check each time it doesnt feel right until you get some faith in your readings.. it just comes with experience.

 

[hiboy]

thanks alien.

So I just did a recalibration with the 6.86 first then the 4.0.

I tested the store bought purified water and to my surprise it came out 5.5

I tested my tap water and it came out 7.0.

does this sound fishy? I mean purified water should be neutral right?

No amigo,
your thinking ppms more likely, which is a measurement of chemicals/nutrients. But even purified water may not be so pure.. hhaha
h

 

[GrimloxK]

so heres the thing...I used the same purified store bought water for my first grow..exclusively.

If it wasn't for light burn I would have yielded 3 ounces on a sub 3 foot plant.

but I just found this article about the dangers of purified water to the human body



now on my first grow I did have some serious problems during flowering...but in the article it says that using purified water does hydrate well but the tradeoff is the removal of trace particles...

I think I might start using tap water from now on.

 

[Alien Abductee]

No amigo,
your thinking ppms more likely, which is a measurement of chemicals/nutrients. But even purified water may not be so pure.. hhaha
h

haha.. yeah my tap water is 300ppm and the purified is 30ppm.

 

[Alien Abductee]

so heres the thing...I used the same purified store bought water for my first grow..exclusively.

If it wasn't for light burn I would have yielded 3 ounces on a sub 3 foot plant.

but I just found this article about the dangers of purified water to the human body



now on my first grow I did have some serious problems during flowering...but in the article it says that using purified water does hydrate well but the tradeoff is the removal of trace particles...

I think I might start using tap water from now on.

I know General hydroponics makes special versions of their nutes for hard water. I have found I could use tap water if i used the hard water formula. My tap water is around 300ppm out of the facet.

When I use purified water, I don't use the hard water formula and have the exact same results.

As long as I plan my nutes with what water i am using, its been fine for me.

I think it has to do with the calcium in the hard water, can lock out or be deficent.

 

[ttystikk]

Most hardness in municipal tapwater is dissolved calcium, and can lead to nutrient lockout issues. It can also be a pain to use if you're trying to run low nute concentrations for young/tender plants. Nothing wrong with purified water by itself. If you run it, be sure to buy a cal/mag supplement and use some. I generally start with 1/4 the dose they call for on the label and work my way up from there.

Onto the pH issues with purified water. The buffer solutions you buy are SALTY (stick your TDS meter in one sometime!) on purpose, so they stay pH stable for as long as possible. It's easy for the pH tester to read that way. Since purified or RO water is the opposite, the pH meter has a tough time reading it at all- and the less dissolved salts in the water, the easier it can fluctuate, because it takes smaller amounts of minerals to change it. After all, pH is just another way to read acidic molarity, or acid concentration. That's why pH always goes up when you add water to your res...

The instructions I read are very clear NOT to store your pH meter in plain, purified or RO water- I'm not sure why, they are just very consistent on this point. Their recommendation is to store it in pH 7.0 buffer solution. My bet is the 6.86 stuff you have will work fine for this purpose. pH meters do have a tendancy to wander about a bit in their calibration, so you do need to test it against a calibrated solution regularly, and that means you'll end up buying more occasionally. It's a wise investment to ensure your plants are getting top quality drinks, with no hangovers!