How measure PH?

[Brent F]

Here was a table from the calculator I was using showing the effect on PH of various Alkalinity increasing products:

Product........................................... ................Effect on PH
Baking soda.............................................. .......Somewhat lower
Soduim Carbonate Anhyd. (Baked B. Soda)........... Substantially Higher!
Kent's Tech CB Part B Alkalinity...........................Higher
Warner Marine CalxMax Part B Alkalinity................ Moderate Increase
Randy's Recipe 1 Alkalinity Part............................Substantially Higher!
Randy's Recipe 2 Alkalinity Part............................Somewhat lower
Limewater (saturated).......................................Substantially Higher!
Aq Systems Reef Evo SeaBuffer.......................... Substantially Higher!
Two Little Fisher C-Balance Part B........................Higher
ESV B-Ionic Original Ca Buff Pt 1..........................Substantially Higher!
ESV B-Ionic Bicarbonate Syst Pt 1........................Somewhat lower
Oceans Blend Part 2 of 2 Part Supplement..............Somewhat higher
Seachem Reef Buffer (dry)...................................Substantially Higher!
Seachem Reef Builder (dry)................................. Substantially Higher!
Seachem Reef Carbonate (liq)............................. Substantially Higher!
Tropic Marin Bio-Calcium Powder (Also Calcium)...... Minimal
Salifert All in One (Also Calcium)...........................Minimal
Salifert KH + PH Buffer (dry)............................... Higher