Hannah Phosphate colorimeter pointers?

[10" Red Devil]

Hello was wondering if some of you owners of the Colorimeter could give me some tips on getting accurate results. I did my first test to the best of my ability and the reading said 0.00 and then 0.01mg/l and then 0.00, then 0.00 when the read direct button was pushed 4 times.

How do you clean the inside of the cuvet? Do you pretty much just use R/O to rinse the inside?

Thanks in advance.

 

[10" Red Devil]

bump

 

[10" Red Devil]

bump