i've got black substrate so that I assume won't really bring out the colours of black rays as much eh.....hrm...damn just got the black gravel a week ago...maybe I can mix in a bag of white gravel or will that make it worst! lol...leopoldi's will bland right in i guess..lol. Would love to get a 2 Aro comm going but tried that with 3 and 4 before and didn't work...hurts to see them fight....