Haha This I have definitely done before. Which is why I was curious to see the results of different temps. thanks for sharing your info @Gtinnel. I did know that there was a variance with the Hanna checkers on its own so I’m surprised more people don’t know of this.Thanks for trying.
It was very good of you and in a way has answered my questions.
With yours and others input I now know I can get a fairly accurate result within test apparatus accuracy without worrying about heating the sample up to 25. Which is useful because sometimes I take a cup of water, get distracted and don’t test till a bit later.
thanks again