Let me see your plumbed mixing stations

[Psirex]

Looking for ideas big and small....

[Steve175]

I have a 150G vertical cylinder (~10% of total water volume) plumbed into my system. It has a 2nd pump which pulls water from it and returns it to the top. When it is time for a water change, I flip a valve to take it off line, flip another valve to use the pump to pump it down the drain. Then I fill it with RODI, add salt, and have it circulate itself for 24h before opening it back up to the system. The nicest thing is that when I (inevitably) need emergency water (when I do something stupid and lose water out of the main system), I have a valve with some tubing on the pump that I can open (after taking the cylinder off line) to add (identical tank water) back into the sump [then add RODI and salt at correct ratio, mix x 24h, and bring it back online]. I absolutely love this system.