you can put water in a holding tank, the chlorine will dissipate on it's own.
I've used food grade garbage cans, holds tons of water. then a simple pump can add water to your DT.
you can use stress coat or prime, I used prime for 20 years before I moved to an RO
carbon block system that treats the water in real time.
Let me clarify, traditionally an RO
system will not remove chlorine, but because I'm running a drip system at 40GPD, the water is in contact with the media 10x longer than a standard system by a pressure regulator rated at 40GPD which eliminates the chlorine. so I do a water dilution, not a water change. I haven't done a water change in 9 months now and my chems are 0 across the board.