Phenol red indicator question

[Collector680]

My test kit came with phenol red R-0004, for use with 2000 Series Comparator. I wanted to replace the reagant when that I was at Leslies. They had R-0014, for use with Residential Series Comparator.

The salesclerk at Leslies said Phenol red is phenol red so it doesn't matter. I am thinking that they are NOT the same since they have different numbers. The R-0004 does seem to be a darker red, but I don't k now the significance of that.

What do the experts here think?

[Watermom]

It does matter. They are NOT interchangeable. You need the R-0004 for your 2000 Series Comparator. They are different concentrations because they are used in different water sample quantities.

BTW -- Welcome to the forum!

[AnnaK]

One of them has a chlorine neutralizer in it, the other doesn't. I cannot remember offhand which is which.

[Watermom]

Actually, I think they both have chlorine neutralizer in them.

[waterbear]

The BOTH have chlorine neutralizers in them, The difference is the R-0004 is more concentrated since it is used in a 44ml water sample while the R-0014 is used in a 9 ml water sample. The larger water sample in the 2000 series comparators provides better precision for the acid and base demand tests.

[AnnaK]

Thank you both for clarifying a misunderstanding I've held for some time.