When going into flush cycle, is the Grobo suppose to dose new water w/ nutes?
No. Do a drain and fill after day 1 flush if your worried.
You can disconnect bottles 3, 4, and 5 as an added level of precaution.
That’s what I did. But why not 1&2? Im using RO
1&2 are simply to control the pH of your water. They are naturally occurring additives that should be used during flush.