I have a mixing station in an adjacent room that's heated and cooled. I also have a sink in my basement man cave where the tank is. I have 1" PVC pipe plumbed from the mixing station through the wall under the sink. I have valves and barbed fittings that I attach a 3/4" ID clear tubing to to pump fresh salt water to my tank or RO/DI to my ATO reservoir.
When I remove water from the tank I siphon it in to a 32 gallon Brute on rollers and roll it to a window where I put a pump in and pump it via a garden hose to the woods in the back of my property.
All said it takes about 10-15 minutes to do a 25-30 gallon water change without lifting a single bucket.
Under the sink in the man cave.
The fitting to attach to water hose for emptying the Brute full of old water.
Mixing station....you can see the two different pipes for RO/DI and salt water.
My home made method for attaching the clear tubing that sends new salt water to the tank.