I need a blue fish

Just one. Strangely enough, although they're schooling fish in the wild, they tend to not get along well with their own kind in captivity unless you have a mated pair.

 

To an extant but they still evolved the same way. IME Damsels defend a small territory around there favorite rock,coral,invert,etc...Much like there Clownfish cousins.
If you understand that they really make perfect aquarium fish.As long as you feed them they will not want to move.Also keep in mind There are lots of species of Damsel fish.
Most are omnivores but some are planktivores and herbivores.Planktivores like the Starkki are much more docile ime.There are some aggressive fish in the damsel family but as long as you understand there needs they make some bulletproof additions to any reef tank.New comers are at most risk so choose wisely. Mr. B is right....again.....

 

Just get one. They won't school and will need their own territories.

 

Here are two of mine looking really mean.



The domino was hiding- he's camera shy.

 

Buy blue assessor I got 2 or blue neon guby put some blue Zoanthias

 

The zoanthids are lovely. I've had some tubbs blue for years, used to frag them for people and then zero growth for the last 18 months. Go figure.

 

put some blue corals help a lot











Blue chalices a lots blue

 

I'm sorry to hear about your Royal Gramma. I also had that problem. He was doing awesome since the day I got him, eating without hesitation twice a day. Then I found him floating near the overflow one morning. From what I've heard, it can just happen without much of an explanation.

As far as a blue fish, I also agree with a Damsel. I was also just curious, you said that Chromis are expensive. How much do they go for where you live? Maybe it's just where I live, but they are usually sold for $4-7 a fish here.

 

Petco sell it for 3$

 

The common blue/green chromis are inexspensive but the blue reef chromis are closer to$20 each in most places.