How to adjust PH

[ldyharley]

HI,
Just bought a PH pen, my ph tested 8.2 with test kit, and 7.9 with the pen, how do I adjust the ph up. I have read my books but it does not say how to adjust the ph. So I need some help again. Thanks in advance.
Julie:o

[freddie40]

Julie,

I would worry about such a discrepancy. Have you calibrated your PH pen properly. I would do this before trying to up your PH.

Dave

[ldyharley]

i calibrated the pen like the directions said. i calibrated with the 7, and 10 soultions both. That is what it said to do.

[freddie40]

I realize that this would be a bit of work but I would try this. Go to the store and buy a box of Borax (king soopers sells it in Aurora). A 4lb box costs about $4. Mix 1/2 teaspoon of Borax with 1 pint of RO water (I actually use distilled - close enough for this test). Then take the temp of the water. When you have the temp look at the chart below to determine the correct PH. Lets say the temp was 72 degrees Fahrenheit. The PH of the solution would be 9.207.

Use your probe to see what it says the PH is. If it is off you could actually calibrate the probe with this solution.

The reason your upper level is off may be this. The 10 calibration solution is very unstable. Because of this you may not have calibrated your probe properly. Using Borax you can eith verify that you have correctly calibrated your probe or use it as the upper calibration fluid. This is hat I do with mine.

Too bad you aren't a little closer. I have a lifetime supply of Borax and I would have shown you how to do it. I do hope these instructions are a good substitute though.

Good Luck,

Dave

----------------------------------
TABLE II
pH of Sodium Metaborate Standard Solution
at Various Temperatures
(3.80 grams Na2BO7 10H2O/liter)

1st Column - (degrees Celsius)
2nd Column - (degrees Fahrenheit)
3rd Column - pH


0 32 9.464

5 41 9.395

10 50 9.332

15 59 9.276

16 60.8 9.266

17 62.6 9.256

18 64.4 9.245

19 66.2 9.235

20 68 9.225

21 69.8 9.216

22 71.6 9.207

23 73.4 9.198

24 75.2 9.192

25 77 9.180

26 78.8 9.172

27 80.6 9.167

28 82.4 9.155

29 84.2 9.147

30 86 9.139

35 95 9.081

40 104 9.068

[ATP]

You may want to look at the Reef Chemistry Forum here on RC. A sticky titled "Reef Chemistry Acticles" has a lot of information by Randy Holmes-Farley, et. al., including PH, PH meters, Alk, etc.

Also, wetwebmedia.com has a lot of information on everything reefing! :D

Sometimes reading the information, and having a reference book/article to review helps. At least it does for me.

PMI

[ATP]

Sorry,

I forgot to say I agree w/ freedie on the Ph meter calibration. My Ph pen showed my tank's Ph had dropped to 7.1! However, I checked it versus a test kit, and found I just needed to calibrate it again. Ph was really 8.2. :rolleyes:


PMI