HI Dendro
Which gorgonia do you mean? This one?
The bright yellow gorgonia is a Menella
The Menellas can get quite large, mine were both around 25 cm (10") in diameter.
I don't have much issues with algae on the Gorgs, even when they are under 400W MH, but I have really low nutrient levels, a whole bunch of algae eaters as well as a pair of dragon gobies (Amblygobius phalaena) plus a Salarias segmentatus. If there is a slight overgrowth it will be eaten in a day or two. Very rarely do I have to remove algae by hand.
Food for Elisella is a pain, as I never had any long-term success with this species all I can tell you is what does not work, and that is cyclop eeze and the like. I just don't have a clue how to keep such fine Gorgonias over a longer period of time.
jens