Hi Creetin!
Thanks for inquiring. I am quite flattered to be included as a person to ask about giganteas since I am still relatively new to keeping them.
I agree, I LOVE them and they are my favorite. However, as Tobb mentioned, I also have a thing for Haddoni's.
For me, it is definitely important getting a strong one to start. I also feel they exhibit some 'body language' well and one should be sensitive to how they hold themselves as an indication of what they may need when they are stressed. The ones I can't stand are the vendors/stores that sell them as soon as they get them in.
The following input is just based on my experience. I do have more than 2 right now, and I am in the process of upgrading to a 150 cube. I would like to do a Gigantea only tank with a couple of clowns.
Currently, my tank has 3 tunze and 1 vortech along with the return. It's an Elos system 70. I feed my nems every 2-3 days with a baster, which is usually a mix of Hikari 'S' pellets, Hikari mysis, PE mysis, cyclopeeze, rotifers, Rod's food, and some plankton cubes. The mixture is left to thaw with enrichment added.
I do weekly water changes, about 25% each time. If I happen to feed heavy that week, I do a 40% water change.
I purposely seeded the tank with macro algae. I decided I didn't like the caulerpa because it's so hard to trim due to the growth pattern. This stuff wraps itself around the rocks so tight, it's not easy to remove.
So, then I added red macro to overtake the other type of macro. It's working so far. I hand pluck the macro, otherwise I just leave it and it looks very ugly to most reefers. I happen to think algae is good as long as it isn't allowed to take over.
The reason I think it's important is because when I pull out a chunk of algae, there are so many little critters that run out of it. Not only do I think these guys are important to the tank environment, I also think they provide some good nutritious (and more 'natural') food to the nems.
I also have aiptasia in with them. I would very much like to see them gone, but I just can't bring myself to put peppermints or copperband in that tank for fear that something will happen to the nems. So I just leave them and try to ignore them. I was told any nem would beat out aiptasia so I'm not as worried. It just looks ugly, that's all.
My temperature gets as low as 80 and sometimes as high as 88. It mostly stays between 82-84. I think Anthony Calfo does not like having temps so high, I'm not certain but I thought I saw that somewhere on WebWetMedia.
Good Luck Creetin! As I mentioned before I Love, Love, Love them so much and worry about them constantly. Even the ones I have had for more than a year.