If the dot disappears at the very top of this tube is CYA 30?

[CoolHome]

Hello, my testing tube is from the Taylor K-2006 FAS-DPD Test kit. Picture below. I've been adding stabilizer very slowly because I felt like it was just too high last year and I was using a ton of chlorine. I'd like to keep it between 30-40. Right now if I fill this test tube to the very top (the part of the right) of the wide mouth the dot is gone, so can I call this 30 CYA (or at least more than 20?) I'm just not sure what the top of the tube indicates. I'd like to keep it here if I can officially say 30. Thanks!

​

 

[magiteck]

We always round up, so if the dot disappears when filled past 30 then you would round up to 30.

 

[CoolHome]

We always round up, so if the dot disappears when filled past 30 then you would round up to 30.

Thank you magiteck! I just wasn’t sure if I could trust anything under the 30 line.