Have to admit when sphelps first showed pic.'s of his lionfish and seahorse together I thought he was crazy. Also thought that for sure the lion would eat the seahorse but that never happened and seeing pic.'s of how well they still get along together after all this time definitely changed my thinking.
I'd have to agree that a 20g is a bit small (not to bad but bigger is always better
) I do now believe that a lionfish and a seahorse can and will get along fine together.