For starters this is definitely a M Doreensis, also known as a LTA.
If he has "found a spot" but is not attached and is laying on his side, he didn't find a spot he just blew to a low flow spot in your tank.
Can't see what is on his side due to poor picture quality, it's either sand or tissue. Reach your hand in and try to brush it off, wear gloves if you might be allergic. If it brushes off it's sand, if it looks attached it's tissue.
Did you say you added more sand to the tank?
I've seen a lot of Nems do okay in what most would have thought was poor lighting. Your light is nowhere near suitable for that Nem and may be part of why it won't attach. It wants more light.
I don't often say this, but you really need to get rid of this Anemone and slow down if you want to be successful in this hobby. I went back through your post history and your first post was basically you killing everything in your tank as of July 18th from simply going to fast. You may or may not have moved your tank at the start of August? You had a maroon is it still alive and in there? Your approach to reefing appears to be, you getting a little bit of information from somewhere, going for it then coming here and asking very very basic questions, many of which are answered in the stickies in his very forum. There is essentially NOTHING we can do to help you if you are not willing to take the time to help yourself.
The bottom line here is this, your lighting is not strong enough for this creature, your tank is not stable enough (especially if you added sand to try to help), you're going to fast and you really need to just STOP, slow down and try to learn. Reef-keeping isn't a learn as you go hobby. Don't get me wrong you definitely learn a lot as you go, but you will save yourself a lot more time, hassle and frustration if you learn as much as you can before reaching for your pocket book. You can throw as much money at this tank as you want, but you're going to continue to just kill everything over and over and end up just getting frustrated and selling everything if you're not willing to slow down and do a little research (more than just asking questions. Read the wealth of information here then ask question if you have any).
I'm sorry I very rarely recommend somebody get rid of an anemone, but based on your tank history, this is one of those times where that things chances of survival are very slim with the current state of your tank.
