Awesome thanks for the info guys, much appreciated.
I got home last night and finished making up water for the 20L along with about 5gal from my display, got the tank in place, brought to temp to match the 10gal, and then put 1gal from the 10gal in a bucket with the angels. After a bit I added 1gal from the 20L and let them acclimate for 45-1hr, then put them in the 20L and went to bed. I woke up to the Cherub dead and the Potters breathing fast but swimming normally. I added an airstone and checked ammonia, salinity, temp and all checked out normal. The Potters took a few flakes of food, but i'm worried about the fast breathing. The only thing I can think that I might have done wrong was not adding more water to the bucket during the acclimation. They were so lively last night when i got home, ate like pigs. Makes me wish I had just put them into the display from the start, but then again I'd probably be trying to net all 5 fish and have to go thru this whole process again in a few weeks with my luck lol