I just put in a BRS deluxe system and bought a Hannah checker a week ago. Checked the RO water as an experiment/practice run with the checker. Came up 0.
My system is well water in, whole house sediment filter, booster pump (85-90 psi), standard three premembrane canisters, RO membrane, 2 canisters color changing DI resin. I added an additional TDS meter to the one that came with the set-up. I have TDS 226(ish) going in to first premembrane cannister and 237 Coming out of the the last canister before going in to the membrane. I find this odd and thought that I must have reversed the probes. Must have checked it 5 times. If something is reversed it is inside the TDS meter. But I digress.
TDS out of the RO membrane is 7 (approx. 97% rejection rate). Coming out of second DI canister is 0. Membrane is listed at 75G per day. Calculated production is somewhat higher than that but I do not have my notebook handy. Waste water to product ratio is 2.8:1.
Instructions with the BRS system seemed minimal but I followed what they sent and it has been prefect for the first 50 gallons of product.
Sorry for the BRS review on your thread but it is the kind of information I would want if I was having problems with a relatively new system. Good luck.
Mc