Everyone has their own opinion. Considering that its the minerals in the water that causes the pH and hardness of the water. I wouldn't say its irrelevant, otherwise, RO water would be fine. Granted, all EBs are numerous generations away from wild stock, but logic says that if you can give them as near to a natural environment as possible, it should help. I've had good luck with this approach, but others obviously have had equally good results. I was just giving you suggestions of what has worked for me. Once again, good luck with whatever you decide, but I still suggest a UVS no matter what water perameters you choose.
Mark
I have as BIG one on my 180 discus tank but I dont have one on the Jack Tank. I will have to get UV for the EBJD's. Thanks for the tip.
Arkangel77