not yet, but i plan on a couple of tangs to take care of algae on the 6ft prop tanks when i get them sorted, fish poo is good for yuma colouring according to a mate of mine.
i'm reading calfos prop book 2nd edition at the moment and the topic i'm up to is lighting/pigments and how the lower light corals have pigments that glow in low light to recieve the light needed for photosynthesis and if you give them too much light them pigments go away. considering the pigments in question are the brightly coloured ones one has to think about overlighting shaded/deep water corals.