C. racemosa is a competitive algae in high to moderate lighting. Your T5 lighting will work fine. It can be fast growing, it generally creeps across rockwork or sand by runners, is difficult to control, and is near impossible to eradicate once established IME. I would not introduce it to a tank where branched stony coral like Acropora will be kept as it tends to get into the branches where it is difficult to remove. It is better suited to a tank with massive stony coral or soft coral, and you still will need to work to keep it off of the coral. The variants of racemosa I've encountered were not preferrentially grazed by rabbitfish, tangs, or long-spined urchins that I've kept. It can spread from tank to sump or vice versa, I'm not sure wether by spores or fragments. Harvest is by pulling out what you can, it tends to grow prostrate to the rock, is well anchored to the rock, and fragments readily. I would pull out what I could every 2-6 weeks. Watch out for thick clusters of algae where light and water flow are restricted, as this is likely to induce sporalation.
Other choices might be Halimeda or Sargassum. Honestly, where you live there are hundreds of choices. My preference for an export algae that should be found in most Hawaiian islands is Acanthophora spicera, a red branching algae invasive in Hawaii. Most tangs and rabbitfish eat it, I don't know about small angels like a fischer's, I doubt it. It tends to grow in an upright bunch from a single holdfast making it easy to harvest. However, it spreads readily by fragmentation so it can be difficult to control if you don't have a tang in the tank. It likes high flow and high light and can grow gangbusters, outcompeting and smothering many other macroalgae.
I got this nice book of Hawaiian algae from the UofH. Nice photos, also has ID keys. A great book for the price, IMO.
Huisman, J.M., Abbott, I.A. and C.M. Smith. 2007. Hawaiian Reef
Plants. University of Hawaii Sea Grant College Program. / ISBN 1-929054-04-1
http://www.soest.hawaii.edu/seagrant/communication/HRP/