So i have deiced to do a tanginikan setup. i will use as 50 gal. my idea is to have a colony of lamprologus speciosus and a breeding pair of julidochromis transcriptus. i will have rocks and caves closer to the back for the julis and shells infront for the lamprologus. my question is what shells are readily available and that the lamprologus will enjoy. How many lamprologus and julis can i stock.