Sorry my pics are sideways. Not sure why my phone does this.
I have some ideas for you.
My saltwater changes are everyother Sunday. The mixing pump mixes the salt throughout the week in a continuous loop via ball valves so that I always have some ready to go in case of an emergency and I always have an additional 100 gallons on stand by for a total of just under 20% of the systems total water volume.
I ran a 3' piece of pvc with a ton of wholes fir a spray bar affect that mixes all of the salt in about 30 minutes.
Everything below is in less then 10 minutes with no buckets at all.
I trigger a toggle switch that ramps up all of my system's mp40s to 100% (via the apex) in every tank on a random mode for 5 minutes to stir up any detritus and shuts off the heaters (the heaters are in the sump that I am depleting of water and I have one in the sw mix tank).
-During the 5 minutes I check the system and sw mix tank salinity and temperatures manually to ensure that the apex is reading all four probes correctly.
-I open a ball valve from the main return pump that depletes 95 gallons from the system in 73 sec. and then I close it.
-I open a ball valve from the sw mix tank that fills the sump with 95 gallons via the same sw mixing pump and then I close it .
- I open up a ball valve and move the fresh water into the sw mix tank, add the salt and turn the circulation ball valve back into the on position.
I have another 55 gallon plastic barrel that the apex fills automatically in the middle of the week for top off.