the most trusted name in water testing

Can You Interchange Reagents?

Can You Interchange Reagents?

Generally, you cannot interchange reagents between test kit manufacturers. Even though the reagent name is the same (e.g., Phenol Red), it doesn’t mean it’s the same strength!

Reagents are manufactured with a number of variables in mind — the most common two are sample size and view depth.

The same holds true for similarly named reagents even from the same manufacturer. For example, Taylor Technologies makes four different phenol red reagents for testing pH in a range of 6.8─8.4. Four! And none of them are interchangeable (despite what some industry people may say).

Inside Taylor, each phenol red indicator is a different strength based on the sample size of the comparator or system being used. The information below will help you determine the appropriate phenol red indicator to use.

Residential Series™ comparator (5 mL sample size): Use only R-0014

2000 Series™ comparator (44 mL sample size): Use only R-0004

Slide™ or Midget™ comparators (11.5 mL sample size): Use only R-1003J

As you can see, not all reagents are alike, even though they may have the same name.

For questions about reagent interchangeability or any other questions, contact Customer Service at 800–837–8548, or submit your tech questions to us using the following link: