fish agression

i recently upgraded to a 90 gallon tank. from a 40 gallon. the water i used was from the 40 gallon and my riends reef tank. it has the existing inhabitants, a yellow tang hawkfish damsel and maroon clown. but i just added a percula clown a sailin tang and two large blue velvet damsels. there seems to be some agression between the old fish and the new fish expecially between the two tangs, how can i stop this or at least settle it down?

 

in recently i mean just a couple days ago. and one of my friends tanks sprung a leak so he gave me these fish.

 

re-arrange your rocks.

some tangs are just aggressive and will always kill others you put in.

 

i will try this, is there a major chance it will get killed?

 

definitely, they fighting for feeding territory and not dominance more then likely. hopefully the changing of the rocks disturbs the territories.

If they keep fighting even after that its will probably be to the death, although it could take a few months to hit that point(or a few days depends on the tangs).


also let me put it this way, I have had a less then 50% success rate combining tangs. My friend had less then 10% success rate, he had to go through 8-9 tangs before he got one that didn't get killed.

 

I should stress the success rate really depends on the tangs.

I have tried to par a sailfin and a yellow before twice, it failed both times ending in the sailfins death.

 

i have had fish agression, mostly with angelfish. but the tangs dont seem to be violently thrashing their tails at eachother. just when one gets close to the other it just kinda nips at him. his fins arent ripped or anything. also both tangs are relatively new, the yelllow was bought a week and a half ago and the sailfin was a couple days ago.

 

they may get over it if they aren't chasing each other around the tank.

although I have had mild aggression subside and then reemerge a month or so later.(two yellows)

 

i will watch, also this is weird but the first fish in the tank was a maroon clown, the hawk and damsel i bought about a month after him now rule the tank and pick on him to death. he now has ripped fins. he is tiny as well not even an inch.

 

It's because hes probably to small. While I like hawkfish they are kind of jerks and hunt/pick on anything smaller then them. Damsels are pretty big jerks if they don't have good boss damsel or sufficent competition that rules the tank.