First know that there is a very low survival rate on them, but much higher nowadays compared to the past.
If you are getting it shipped to you, ask them to send it in a bag with no air. Just full of water. This was an observation from another poster who has had much success using this method.
Giganteas are very prone to bacterial infection during shipping. And when a sick anemone is introduced to a tank with other anemones they can transfer and cause the other ones to be sick. If its coming from another persons tank (not LFS) and has been very healthy in their tank for long term then you will have great success.
I would suggest that you quarantine it for a week with no other critters and just do full daily water changes. Have a powerhead and heater at one end, and egg crate to separate it. Be careful with light intensity as acclimation needs to happen. When it spits out its zooxanthellae (looks like anemone poop), you want to clear that out.
Then monitor for the next week. If it keeps deflating and pancaking then you need to start antibiotic treatment. Suggest you read the stickys in this anemone thread on that.
Apart from that, they want high random water flow, high lights. They grow fast and have a mean sting to them that will give you a rash for over a week. Also one of the most beautiful anemones.
Welcome to the club?
