Testing for Co2

[DivaSkyChick]

'm having a hard time figuring out my Co2.

The directions on my KH test first say, "The test is completed
when the water in the test tube, after having been shaken, turns from
blue to yellow." But in the next paragraph, it says "when it turns bright yellow."

So yellow or bright yellow? Right now there is a distinct change from blue to yellow after the fifth drop of solution. I can continue adding drops and get a brighter yellow...

Anyone know how that works?

 

[smithrc]

It sounds like the sma kit as ours... ours was blue at 8 drops and yellow at 9.

The dip strips said 8 when i first tested so i assume nine is right.

Id say go with yellow.

 

[Waterloo Kid]

I remember doing titration tests during my A level chemistry. Basically the test you are doing is just like a titration test. There will be a distinct colour change on the addition of one drop. Looks like you hit the spot on drop number 5. The colour may intensify but that's just 'coz you're adding more chemical.

WK