Hanna Colorimeters

[toytech]

Ive checked both my tap water and ro/di , tap was 0.11 , ro/di was 0.00 .That's why we use ro/di it takes the phosphate out of the water , phosphorus is a solid so it would show up on tds . I was surprised first time I used my hanna meter but with proper procedure open the little packet first and empty it onto some wax paper, cleaning vials with vinegar and ro/di , I got very consistant readings.