Would it be best to try to get the YP and SMB going before adding the HSB as they might compete with them while they are small. It seems you could add some HSB once you get a feel of how the SMB are doing. I am thinking with good airation system you might have a chance.
Are you considering fresh water shrimp too?

Goofing off is a slang term for engaging in recreation or an idle pastime while obligations of work or society are neglected........... Wikipedia