I also don't really agree with the wait a certain period of time to get an anemone but you absolutely have to keep good water parameters. I have kept every type of anemone for years and my first was a few weeks after my cycle. The problem with putting them in early is the water is still unstable as you will go through a few months of the tank cycling. The initial nitrogen cycle doesn't mean you're in the clear as far as stability goes. I will tell you if you're really deticated to your tank and keep very good water parameters you can do it and you won't be the first but it will be a lot harder then if you wait until the tank is fully established. Either way good luck with the new tank.