I don't any live plants. A planted tank is a bit above my beginner level at this time.He is very pretty!!
You said "I just started" a 20 gallon.
In an effort to help, I just want to ask if you cycled this tank, have live plants, or a testing kit to help you get thru the Nitrogen cycle? If you answer NO to any/all of these.... please wait to get thru the cycle before you add any more fish.
And we want you to be successful and don't want you to loose any of these fish getting thru the cycle... especially Moondoggie!!
Can you give us a bit more background? We're here to help get you thru!