Need a quick and extremely affordable way to segregate livestock in your aquarium, either because they’re new inhabitants or just a little aggressive at the moment? If an in-tank acclimation/quarantine box isn’t readily available, try using a hamster ball. These clear plastic balls are large enough to hold most fish, and have holes and vents cut into it that are meant to let air in for your movie rodent. Thankfully, these features also make them perfect for housing fish and eels in your tank. Sure, it won’t be secured to the side of the aquarium without some minor modifications, but it’s a super cheap and easy solution that will work in a pinch.