Molly fish bullying new tankmate

today I introduced a molly to my tank which had 2 mollies in it previously. one of them has been chasing and bullying the new one and I'm not sure how to stop it. Ive tried moving all ornaments around as I thought it was territorial but that didn't work. I tried separating the aggressive one in a bag in the tank for a while for her to get used to the new fish. have been fed etc :/ any help would be very appreciated!

 

I have found it's always best to turn off all the aquarium lights when introducing new fish to the aquarium. At least it works for me.

 

What size tank do you have? Whats your parameters? What genders are they?

 

Many times - more fish works better than less. 3 of the same fish often fight endlessly. Add 3 more for 6 total and things calm down.

If it doesn't calm down with 5+ mollies - pull the bully out and move them... Generally everybody else is fine.

 

today I introduced a molly to my tank which had 2 mollies in it previously. one of them has been chasing and bullying the new one and I'm not sure how to stop it. Ive tried moving all ornaments around as I thought it was territorial but that didn't work. I tried separating the aggressive one in a bag in the tank for a while for her to get used to the new fish. have been fed etc :/ any help would be very appreciated!

Maybe give it a day and see what happens. I had 4 Black Mollies, then added 6 more the next week with no issues. But what did happen was, I added 2 juvenile angels last week. I was worried at first because all 10 Black Mollies lined up in a group and was staring down the angels. They followed them everywhere as a group. By the next day they were all settled and peaceful.
Not saying it’s the same thing. But give them a chance to settle in.

 

See that's the thing....

Going from less to more almost always works.... Everybody calms down and things settle down....

Going less with fish like these is where you almost always have problems.

Oh - I want to make sure they don't kill eachother or overstock the tank... So I will start with 2 or 3.... Blood and fish parts everywhere.... Wow - these are incompatible... I better back down to one per tank... Nope - add 4 more and it will settle down.