RO water on its own is not such a good thing adding DWB and AMS would definitely help but as to what quantities I can’t help really help you However a quick look at Brewfather suggests
3.3ml CRS
2.4g DWB for about 28L water
Expected profile of
Ca 22
Mg 0
Na1
Cl 29
SO4 55
Giving a Sulphate / Chloride ratio 1.9 Slightly dry or bitter
Don’t take this as gospel I’ve only been messing about with water profiles for a couple of years and I’m far from being an expert. There are plenty of people on here that know better than me and would be in a stronger position to help you
3.3ml CRS
2.4g DWB for about 28L water
Expected profile of
Ca 22
Mg 0
Na1
Cl 29
SO4 55
Giving a Sulphate / Chloride ratio 1.9 Slightly dry or bitter
Don’t take this as gospel I’ve only been messing about with water profiles for a couple of years and I’m far from being an expert. There are plenty of people on here that know better than me and would be in a stronger position to help you