I'm with Pops on this. Empty the sump totally of water, the display can handle that for 12-24 hours if it's kept moving. The you can slide the sump around, lift up one end and then the other to work under it. You could put some little wood blocks under it to prop it up and let a fan blow under it. Gets some towels under it to dry the floor. Maybe put a vinyl liner type thing under it perhaps (I don't).
Then, you can take it off the blocks, fill it back up, turn on your pumps, and you're back in business. Dry the floor under it, call it good.
But, as previously said, a drip system. That's why I was so keen to have one very early after I set up my 540. I don't do water changes on big tanks like that--I forget, I fall asleep, I go do something else, flood. Not having it man.
I also have one of those digital times on my outside hose, too. I set that thing to run for 12 minutes then shut off when I refill the 125. That way I can't overflow the tank because that takes over 13 minutes.
