I have been thinking about this same thing. I'm going to go to Early's to ask them about it.

I'm currently collecting RO waste in a 65 gallon drum that is outside. I have a bulkhead near the bottom with a hose tap fitted onto it. So I just screw a hose onto the tap and use gravity to hand water the flower beds. I will also hand water a few spots where the underground sprinklers don't reach very well. I have quite a few flower beds though, and I can't keep up to the RO waste water. That is partially because the underground sprinklers get most of the flower beds at the same time though, so they only need a little bit of hand watering.