How exactly does one add fish to these tanks? I've tried taking several types of fish and putting them into the fish tank inventory, but all are rejected. Some instruction would be nice, as simply "drop fish into tank" is not working. Thanks!
The fish tanks are nothing else than containers, just like backpacks. When you have a fish tank in your inventory rightcklick it to "open" and you have the inventory of the tank. Then drag and drop the tank fishes into it, just like you move all other items between containers. ONLY fishes with TANK in their name, not the normal Bass, Trout or such... Edit: From the R113 notes:
You can also just put the fish tank down and double click it, then drag and drop fish from your inventory into the slots for the fish.