All species of Xenopus make excellent pets. I find them most interesting. X. borealis is an excellent choice. It is very colorful and the call is loud. I doubt that it is as loud as a parrot, but you may be surprised. In the wild, they are found in the highlands of eastern Africa at altitudes as high as 7,000 feet. A 20gallon tank should be able to handle 4-5 adult frogs. Would be best to have at least 2 frogs, not because they get lonely but they are entertaining. Keep the temperature around 70(F) or 21(C). Feeding is easy, they will readily take Repto-Min and an occasional night crawler as a treat. You have made an excellent choice and you will soon appreciate the Joys of Xenopus!