Now that you mention it I had 4 chromis and now only have 3. I take it they get aggressive towards each other? cause I have noticed that out of the remaining 3 1 of them looks a lot smaller than the other 2, and this seems to stay on its own.

I am going to take your advice and not add anymore fish for a few months and see how I get on. Will I be ok adding more corals?

Thanks for the advice,

Waggy

The smaller one will probably be the next to die , they will hound it and prevent it from feeding . Then you will be left with a pair of chromis ( dominant pair ) and a pair of clowns , i bet nothing dies after that.

If you want to give the little chromis a chance , re-home him , either to another reefer or to the LFS.

My experience with Chromis so far (about 4 months) is not great. I bought 3 and the next day one was dead. I still have two, and their behaviour is strange. They look like a pair at a glance, swimming around the tank together, but one is much bigger than the other, and sometimes just turns around and has a go at it for no apparent reason, then they swim side by side again for a while, as though nothing had happened. At night they are completely seperate, and if the smaller one enters the cave area that the larger one is taking shelter in he gets chased out of there.

I think what is happening is that they are kind of programmed to stick together in open waters, but under rock cover or darkness this is when their aggressive side comes out. I don't think they need to be seperated as the smaller fish is eating well and has no physical damage, but I think in high numbers there could be real problems with weaker fish.

Possible that they are just sorting out their dominance.

If there are just two left , one will be male and one female. They'll settle down i'm sure.

Minimum size for a shoal of chromis they reckon is 6 in a tank , and they do better when fed often ( 5 or 6 times a day ! ) , this reduces the aggression and calms them down because there isn't such a tussle for food because it is coming regularly , they know that they will get some later. If they are just fed once a day , it becomes 'all or nothing'