Thank you for your response guys, you helped a lot.
So as far as I understood I would need:
1. a trolley or backpack
2. Depending on hardness of my water an DI or RO+DI unit.
3. Pole and brush
Is that all I need to start off ?
Also, I don't quite understand why (if let's say my water is enough for Di filtring only ) I would need an RO on work above 45 feet? Does the water goes hard on heights?
I know that's stupid question, I'm just completely novice.
Another thing is would I really need that DI unit with a resin attached to my backpack and carry it on all the time ( according to last post by barry ) ? I thought that the filtring stuff you only attach to tap and gather produced water in tanks or something.
And the last one : What do you do with waste water ( seen in some Di's description that normally you generate 60% of waste water ) ?
Thanks again and have great workday