I don't have room for barracks,so here is what I do.
A 6' long table(I have 2 right now),the long plastic containers(like you keep spare cloths in)I can fit 2-3 on each table,a heater large enough to heat the water.
Fill the plastic containers with water just enough to cover the heater by a few inches.
Get as many 32oz deli containers as will fit in the plastic container you use,now double that.
Take 1/2 the deli containers and put holes around the bottom and up the side a little ways.
Leave the other deli containers just like they are.
Fill the 2nd containers with aged water,put the ones with holes inside the deli containers inside the other ones,put your betta in it.
Now,get the same amount of deli containers,the ones that don't have holes in them,fill them with aged water.
When it is time to do water changes,pull you deli container out(the one with the holes and your betta,place it in a clean cup,dump the water out of the old one,refill,and you are ready for the next water change.
Lucky for me,I work in a resteraunt so I can get deli containers fairly cheap!
I partition the cups with cardboard so the can't see each other,pull the cardboard out so the can flare now and again.