I guess I'm up grading!

the most important thing, besides not flooding the house and basic stuff like that, is making sure the corals are okay. I put all mine in one big container with a heater and a power head.

You have to remember, you'll need empty containers for the current tank water, then new salt for the rest of the volume. I like to bring an extra 10% of total tank volume in extra water just to make sure.

Fwiw I would try to go bigger on the sump if you can. I have a 20 under my 50.

 

It will be closer to a 29. I'm not sure we can fit anything bigger. What if that's all the bigger I can go, is there repercussions?

 

Not at all bigger is just always better.

 

Whew! Because it's a corner tank and I'm thinking the 29 will be pushing it!

What's the benefit to mixing my own water? I have always just bought water, is it just cheaper?

 

cheaper, more consistent results, "fresh" water, idk, I like the idea of being able to do it myself. Most stores don't use the higher quality salts anyways.