Getting Mr. Betta Out Of His Shell

[isadorala]

And I mean this quite literally... I have a newly acquired betta in a 70L tank he so far shares with 5 dwarf rainbow fish which is planted.
 
Basically I got him from pets at home as all their tanks were heavily infected with white-spot. The fish were dying on a daily basis left, right and centre and the guy there gave him for a pound basically to get rid of him. To me he looked like the only one who might survive the journey home, so I decided to take him with me. He also gave me some treatment (I had some at home anyway, but it was a nice enough gesture).
 
I had to put him in a hospital tank (didn't want to pass it on to the rainbows) and he survived the treatment. The downside. He was in a small tank (still bigger than his cubicle at the pet-store, but only just) with no real lighting for 2 weeks or other fish and the room I had to put him in wasn't particularly lively (no lid + cat = cat-proof room = guest room). Now however it seems he has become agoraphobic.
 
He's been in his tank for 5 days now. He hides out in the coconut shell on he bottom of the tank, only rarely venturing out to the planted area to hide there, and anytime I approach the tank or rainbows get near him he goes straight back to his hidey-hole. I've observed the rainbows, and except that first moment when I put him and they checked him out, they haven't been nipping him or anything.
 
Will this pass or is there some way I need to convince him the big world isn't so scary? I'm not sure if it's because he's afraid of the rainbows or if he's still feeling under the weather. But I don't think keeping him longer in the hospital tank would help him in any way 

 
(I haven't named him yet so any suggestions are welcome btw )
 
Hope anybody has any ideas 

 

[RCA]

Bear in mind that he maybe has only been used to very small spaces and he needs time to realise that it is safe to explore this larger world you have given him.  Was he in with other fish at the LFS?  Some of my new bettas have been very shy to start with, but give it time and he will soon be hopefully wiggling at the front every time he sees you.  Are you able to get him any live food?  The best is white mosquito larvae (glass worm) as this is their favourite and typical to their natural diet.  Seeing this move around will encourage him to come out and hunt.  In time he will associate you coming to the front as being the bearer of food.  Keep an eye on him though, and test your water, just to be sure all is well.
 
Keep us posted on his progress... got any pics of him to help name him?  What colour is he?  Do you know what type of Betta he is e.g. Veiltail, Halfmoon ...?
 
Oh, and well done for Quarantining him and getting him well.  I note you state this tank had no lid?  For future reference always cover a Bettas tank as they are jumpers.  A cheap way to do this with a small tank is buy a couple of glass place-mats and put them on top of the tank, this lets the light in but keeps Betta safe.  Plus if it needs to be more secure (cat proof) add a large paperweight on top.