You know this is my very first post on this forum...I joined to post something else but since my gf has an ACF I thought I'd just pop in.
Who the heck are these people saying it's ok to stick relatively large animals in tanks just double their size? And use defenses like these animals can't talk so they can't tell us they're unhappy or not...so they must be happy!
Look, we're all jerks for keeping any animal in an environment that isn't where they are naturally from even more so for aquatic and avian animals. But we should responsibly keep them or at least admit that we cannot keep them properly when the time comes.
Seriously, get a 10 gallon, the footprint is not much bigger and the cost is probably just around the same...so why not? You could probably go even cheaper and get one on clist used.
My gf had one, in one of those 5Gallon acrylic pet carrier for years. Her dad took over and never did a lick of research. It lived in that carrier for 8 years not a single plant, hide, filter, or anything with a water line that was only an inch above it's body flat (the old man thought the frog would drown with more water...yeah...I still have to add water when I go visit). But I bought a 10g and supplies for under $20 from petco. 8 years! Honestly, I think about euthanizing the thing all the time.
Can an ACF live in bad conditions? Sure. But don't just don't.