If their RO filter is good the gH, kH, should be zero (at the resolution of our kits) and the TDS neer zero. The pH can vary, since there is ery little buffering capacity to the water, the pH can change easly.
Ussually, TDS is a good measure of RO water quality.
I've recently switched to RO water from LFS. What parameters should this water have? PH=7, GH=?kh=?, TDS=0 etc..ect...any help much appreciated.
My RO system reads 0 on everything beside the PH, which is 6.4. i dose 2tsp of baking soda in my 50g during water change to bring the KH to 2dgh. GH is also increased by adding Ca and Mg to desired levels. i add 1-2tsp of Ca and 3tsp of Mg during water change only.