Hello! Welcome to the frog forum!!

Colorado river toads are quite poisonous so you must be very careful around them.

Yes, they can cohabitant. They should-need to be the same size in order for it work. Females are larger than males but that usually isnt a problem.

Colorado river toads also get quite large, quite. A 30-40 gallon tank should be used. The 20 is ok for a little while if the frogs are young but if they are sexable then you would be much better off with the recommended size.

A quarantine setup is necessary in order to ensure that you know your frogs are healthy. The setup should include:
-damp unprinted paper towels as substrate
-a water dish filled no higher than the toads chin
- a place to hide

Have you looked at our care sheet? It really helps !