Journal UNS 150U - Nature Aquarium

[JacksonL]

My 20 year-old eyeballs were much better at seeing end points in phenolphthalein titrations, than my eyes now My schedule isn't quite so ridiculous today, so I will check it again tonight before the CO2 switches off. Brighter light does make it easier, but I am probably still reading it a little high.70 seemed crazy high though, for not even a full pH drop, which is why I didn't believe that value.

How old is the test kit? Be careful of older or not well stored reagent with the CO2 test. The first kit I had, I was quite blasé with recapping the bottle and after 6 months of use the weaker reagent caused crazy high readings.

 

[Kwyet]

How old is the test kit? Be careful of older or not well stored reagent with the CO2 test. The first kit I had, I was quite blasé with recapping the bottle and after 6 months of use the weaker reagent caused crazy high readings.

That’s what I found too. Even though it wasn’t expired yet, I had to buy a new bottle to get reasonable readings again. Now I’m careful to recap the bottle tightly immediately after drawing from it.