Unbelievable! Look at this, it's almost disgusting!

[Delphinus]

IMO it's more about adequate water movement and gas exchange, of course lighting is important too. But an 8 lamp T5 unit is going to be fairly bright ... I don't see it being a limiting factor.

Unfortunately gigantea has a terrible track record for melting within the first week or two, it seems they are very prone to picking up bacterial or other kind of infection during collection/shipping/retail. Nobody really understands why this is. If you can get them past the first month though they're pretty hardy. These anemones are my favourite species, they just look cool in my opinion, although haddoni's can come in brighter colours (nothing can compare to a crimson red haddoni). But haddoni's get larger, and are prone to eating fish, whereas gigantea's are better behaved in this regard.