Was curious if it would be okay if I bought a couple Critter Keeper's (medium size) just to have on hand for quarantine or a home for a Betta? I'm not sure how much water they hold the online store only displays it's dimensions. I think I've seen a couple people here using them, but wasn't sure if they were using them permanently or for other purposes. At my LFS they have these under-gravel heaters I think their 10Watts and I think would be perfect size for a Critter Keeper and I'd really like to have a couple of these things on hand for my impulse Betta buy's or Betta rescues.
If this won't work then I'll have to slowly build up 5gal set's. I have the perfect bookshelf to use for both idea's.