Not to be cruel, but I think a 16 gal is to small for zebra loaches, way to small for clown loaches.
Most loaches do better in large groups, they are very active social fish. Group of loaches also establish pecking orders, so having only two could cause conflict. One could dominate over the other.
I would like to see you have a group of them, but a 16 gal is just to small for that. I think it would be best to returm the loaches or keep an eye out on Craigslist. Sometimes you can find awsome deals on used aquariums.
Last edited by Twistersmom; 07-02-2009 at 06:04 PM..