Guess im not a good chromis owner

I'm shocked to read about lots of people having issues keeping these!!!

Not to rub it in but I must have been lucky - I had 10 in my tank for almost 4 years with no issues. I added 10 initially because I figured i would lose apx. 1/2 but they were schooling from day one and ruled my tank til I gave them away when I moved. Easy fish to care for and feeding once a day is fine also

BUT

With a 46G you could only keep a small school and IMO any less than 6 they seem to build a pecking order and thats when the problems seem to start. For your situation you may want to consider a different fish.

 

I read a good article on this and thought I shared but it was awhile back. The theory is; Blue/Green or Green Chromis like to belong to groups. The catch is, they, for some reason, like odd number groups. In your case (Puffer) if one was eaten, that left an even number so another was killed. When we purchase these fish we don't know what group is what in the LFS tank, they do (the Chromis). In the chaos of netting them groups get broken up and two different groups may now end up in your tank with an elimination of members from one group or the other. An ideal purchase may be to go to the LFS and if they have say 5 in one small tank and all are well, those five are a group and may be fine in your tank. The person here with the 10 probably ended up with 2 groups of 5 that formed a super group if all swam together.
My original group of 6 (bought before I knew about the odd number theory) got down to 3 and I have had them about 1 year or so now.

 

This explains a lot. K+ for this post. going off of this, I have noticed that my 7 do not school as I would like, 2 of them, the old one and one of the new ones are constantly together, can I expect them to slowly pick off one at a time, or do you think with time they will school?

(don't mean to steal your thread PC, just think this is interesting info on chromis)

 

Since the old and new have "partnered" it may be a good sign and all seven will stay intact. There is the possibility the group will go to 5 or 3 though. As far as schooling, I believe I read that you would need a long, large tank for better success but can't remember a starting size.