To your question on if there is an anemone, that doesnt move. They all move around and at different times for different reasons. Most of witch are due to water quality. Which is mildly noticed. Water quality, feedings, nutrints, and light normally determins how often its open and its general size when open. To help the anemone attach to a surface. Once u get it home beginne aclimation as u normally would. If u aclimate your aquarum live stock by placing the bag in your tank for 15 min continue to do so. Once it has been aclimated and if still in the bag. put your anemone in a seperate container like a breeding box that hangs on the side of your tank with a large rock inside. It should attach itself to the rock. If u dont have a container big enough get a bigger container like a 5 gallon bucket with some rock covering the bottum. There are times it may float around some hobbiest use a loose rubber band to timporarily hold it to a rock. Personally I would not do this because it can be harmful to the anemone. It can take some time for the anemone to settle at the bottum and on the rock normally in 1 to 2 hrs and some times sooner. After it has attached and has been introduced to the aquarium they may move around. If expossed to por water quality for a period of time it will gradually move around most often noticed by the foot or its base and if it seams completly attatched or partially. Anemones will often move if it feals unsafe. Mostly due to over agresive fish including clown fish when first being introcued to the anemone. So its best to introduce them both at the same time. The clown fish will normally help the anemone attach it self to a serface, but if the clown fish is too agressive, like the marron yellow stripe clown to most bubble tip anenomes of any color. Death may result there after or with in a few months. Clown fish will commonly clean the anemone of dead tinticals and as well help feed the animone. Bubble tip anemones are non agressive eaters. They will suck on food instead of eating it whole if the piece is too big and even at times with small pieces. Some hobbiest insert small pieces inside the anemone mouths= the whole in the center of the anenome. This feeding style is normally done with bubble tip anemones and normally requires observation to insure that the food is eatin by the anemone. This is most often how clowns pull anemonies apart from the inside resulting in death there after. This is only due to the way buble tip anemones eat by sucking on food releasing enzymes which slowly desolves food. On the other hand u have carpet anemones which are agresive eaters. They with pull whole pieces of food into there mouth closing up completly around it. Bubble tips anemones use this similer technic but only to suck on the food as they eat it. So carpets anemones require less maintence after feedings and grow much more faster than bubble tip anemones. Some times anemones go almost flat normally due to lack of food, por water quality and some times lack light. Even though anemones eat food they also need to synthasize nutrients through photosinthisis which help it creat enzyemes to help it break down food. Helping it complet its nutrient cycle. In my exerience anemones do best under metal halid lighting. U should be safe with introducing fish, and even your anemone after cycling your tank. Cycling your tank is to help stabilize the water in your tank chemically so that your tank has a natural way of transforming harmfull chemicals or waste to a less harmfull chemical nitrate. Even Nitrate has been seen to be harmfull over a long period of time and will even cause death in fish if reaches 1000ppm. Normally advised to maintain at 25ppm or less some 50ppm or less normally deternined by the fishes activity in the tank. Ironically there for is the need to do water changes ever so often to help reduce the lvl of nitrates in the tank.
Okay back to anemones Ive had green, white/or pink tip, true rose anemones and even a green carpet anemone. The only one I had a problem with was the pink tip or also known as rose tip bubble anemone. It tried eatting several pieces of coral I had in the tank even to the point it would just attach itself up side down on what ever piece of coral it was trying to eat. Unfort. the pieces partially died there after, but grew back with time. Oh yeah I forgot my green carpet ate one of my blue tanges. The only reason it was eaten by the anemone was because the tang was sick/ it was weak, so there for it just couldnt move fast enough to escape. Also there are some fish that like stealing food from anemones like blenies. Well if u plan on just having a clown with him u should be safe. Its really not as complicated as it may seam or even sound. I wish u the best of luck. lol sarry bout spelling spell check isnt working