You need to count the total wattage of lighting you have fitted on the tank. Do not skimp on lighting when it comes to anemones. The three watts per gallon is a guide to avoid having too little lighting. As I stated before, 4 to 5 watts per gallon is preferred. This method has always proved successful. High light coral such as acropora require 7 to 9 watts per gallon. Deep reef coral do not require much lighting and can do well in any light that isn't bright. Anemones, mushrooms, polyps and such do best between 4 and 5 watts per gallon, but nothing less than three watts per gallon for any coral with exceptions of deep reef coral.
"Moderate" lighting in reef terms is the lowest on the so many watts per gallon scale. You have to count and add up the wattage you currently have. I can't do this for you.
This type of math is important for a reef. Anemones and corals that are photosynthetic rely on the lighting to grow a zooanthellae algae in their tissues. This is what gives these coral their browns and greens. This algae is then converted into sugar which tends to the animal's metabolism. If these animals are deprived of proper lighting, they start to lose their color and fade to a slow death...sometimes taking up to a year to die from lack of proper lighting.
Even when an anemone is hosted by a clown or some other fish, it does not suppliment the elements it gets from the lights. BTW
...there are no guarantees a clown will host and if they are paired, you still have to have proper lighting and supplimental feeds of regular food such as squid about once or twice a week to keep them healthy.
We, as a people, know so much more about outer space than we do about our own oceans. This lack of knowledge can very well spell the dangers that lay in wait for us.
The oceans surely would swallow us before a rock comes down to smite the planet of it's life.