I haven't kept them but do know from others who have that all Tropheus species should be kept in a species only tank...they only eat vegie matter. This site should help you out. http://cichlidforum.com/profiles/results.php?genus=212
Yep, ^. I'd suggest species only tank and a colony overstocked to control aggression. What would you like to know specifically. I wouldn't use anything under 55gal for them, though even a 55gal really isn't ideal. 75+ would be great.