I have a divided 5 gallon, and I do 50% water changes once or twice a week, and it's cycled, haha. I believe only smaller tanks require to do 100% at all, unless for some reason, you don't cycle.
Cycle fishless first, it seems easier. Then 20%ish a week seems fine.
Go to craft sections and/or craft stores for "PLASTIC MESH". Then go buy some report-folders, and take the removable binders from those.
If you really want to go indepth, go over to the "betta fish bowl/accessories". There are lots of info over there that would really help you.