Thanks folks, he seems to be holding onto food just fine now and he attaches nicely to things. I clouded up the water last night searching for a sand shifting starfish in my refugium and he got annoyed and moved, but he attached to the glass again right away. His tentacles are slowly getting darker, and around his mouth is much darker now. Thanks for the help and suggestions folks, I feel quite confident that I can recover him. I look forward to showing pics of a nice brown LTA in the coming months!

Wow, and just like that he's gone :-(

My new uber lights seem to have brought up the temperature too high (I don't have them hanging yet they are sitting on top of the tank), but here are my water readings:

temp 27.9C
Ammonia NH4 0.1
Nitrates, NO3 < 5
pH 8.38
KH 10
Salinity 1.027 (we are slowly fixing this)
Calcium 450
Phosphates PO4 < 0.03

So my temp was too high and my salinity was too high. Would those possibly be the cause of his demise? Everything else seems so happy in the tank...

They are quite delicate and need a stable mature tank especially if they are really stressed. So it was a combination of things.

Was there any indication that your nem had previously been dyed? I bought a neon pink sebae anemone from wai's that I think came from the same tank as the one you got, not too long before you got yours. There were a couple others in there that were that colour. I didn't know that people actually dyed anemones, but when I got home and transferred it to a bucket for acclimation, the water it had come in was tinted pink, and the next morning the skimmate in my collection cup was also tinted pink. I looked it up, and it's apparently a pretty common practice in the Philippines. I took the anemone back that day, as the general consensus is that dying them kills 99.9% of the anemones that go through it, and if they start to expel the dye, it's common for them to expel all of it, leaving them really, really bleached, usually followed by a slow demise.

so far I bought 2 sebae that were bleached. One died and the second one make it because it was eating like a pig from day one and I feed it tons of mysis each day.

It went from a tiny 3" bleached thing to a huge 12" brown anemone with a green hue on the top of the body. It had lots of symbions now but I keep feeding it each day. It is home to my 2 clownfish.

The only hope with such anemone is that it eats. If it does not eats it is lost.

I don't think heat alone killed it, but a combinaison of water quality issue (ammonia should be 0!), heat and lack of food.

Once this tank matures some more I may give another anemone a try, but for now I will focus on other creatures. I will also avoid buying a bleached anemone in the future, even if I can save them, it's so stressful! I've only done corals until now so anemones are new to me (as is this tank). I've learned a lot over the past little while and hopefully the next one will go better for me.