my fish are fighting, please help

[2ndThief]

my lawnmower blenny decided it would be cute to start attacking my black clown, I've had the clown for at least 4-5 months and the blenny for 2 and they have been fighting for the past couple hours and it is pretty viscious, I need to get the blenny out asap but it is very hard without moving all of my rock and coral out of my tank which sadly isn't an option. Any advice?

[jer77]

What size tank do you have and what other fish are in it? Is there a problem with overcrowding?

[2ndThief]

29 biocube so actually about 23 gallons. clown, sixline, pygmy, and lawnmower. In retrospect had I known it was 23 gallons and not 29 I would not have gotten a lawnmower, but I do believe it is lack of space and the lawnmower is becoming partial to where the clown hosts.

[demonsp]

Do some rock rearagging if they dont stop but with most new stock they will fight for tank dominance or to show pecking order. Lots of hiding spots in the rock help and within 48 hours should subside. But if it looks to be to much then move rocks around or shut lights off for awile. GL

[Fiddler]

i have 3 chromis in a 30, one stays a bit smaller cause he gets chased every 5 min for a sec ( but they let him eat right next to them i don't get it )

i don't think having those for in a 29 are good, i'm only saying this because you say they are fighting, were the three fish fighting before this?