pH Testing

[waterbear]

The color is the only important thing. match the colors. I really don't underatand what you mean by translucense. Do you mean the intensity of the color?

[cheshamjim]

Evan, I tested my pH this a.m., keeping your suggestions in mind - the color is the thing!

Looks like my pH is at about 7.8, definitely purple, just not quite as intense a purple as the color at 7.8 on the comparator. However, the sample doesn't have that yellowish tinge that the 7.5 scale has.

Since I can't explain what I mean by "translucence" I'll give up on that term and just remember to pay attention only to the color no matter how translucent it is.

Thanks again for your help.

-Jim

edit: maybe intensity is the word.

[waterbear]

Evan, I tested my pH this a.m., keeping your suggestions in mind - the color is the thing!

Looks like my pH is at about 7.8, definitely purple, just not quite as intense a purple as the color at 7.8 on the comparator. However, the sample doesn't have that yellowish tinge that the 7.5 scale has.

Since I can't explain what I mean by "translucence" I'll give up on that term and just remember to pay attention only to the color no matter how translucent it is.

Thanks again for your help.

-Jim
What test kit are you using. Sounds like the problem is your comparator. Some of the cheaper ones just don't match the colors of the indicator very well. the Aquachem test kit is a good example of this! That is one of the reasons why it is worth the money to get a good test kit like Ben's ( or one from Taylor or LaMotte).

edit: maybe intensity is the word.

Intensity of color is where the cheaper comparators usually fail. If you are seeing a purple color your pH is definately about 7.7 or higher. 7.5 will have a definite orange color with just a hint of red in it. 7.6 is a faily pure pinkish red color.

[cheshamjim]

I'm using the OTO/Phenol red testkit that came with Ben's testkit. Maybe I should try to find a better color comparator somewhere?

-Jim

[waterbear]

I'm using the OTO/Phenol red testkit that came with Ben's testkit. Maybe I should try to find a better color comparator somewhere?

-Jim

That's one of the best ones out there and I have found that the colors match up almost perfectly!. Hold the tube in front of a white background (the inside of the lid) in the sun a few inches in front of it.