Help

joshua1800

New Member
View Badges
Joined
Nov 3, 2026
Messages
1
Reaction score
0
What state or country do you live in
United Kingdom
Rating - 0%
0   0   0
Need some advice on fish aggression and compatibility.


I’ve got a 112-litre marine tank and I’m having some problems with aggression, mainly from my Strawberry Pygmy Basslet.


My current livestock:


  • 2 × Clownfish
  • 2 × Humbug Damsels
  • 1 × Blue Damsel
  • 1 × Strawberry Pygmy Basslet
  • 1 × False Gramma
  • 2 × Snails

All the fish are still quite small/young.


The problem:


My Strawberry Pygmy Basslet has started attacking the other fish, particularly the Humbug Damsels and Blue Damsel.


It seems very territorial around its cave and will attack fish that swim too close to it. It occasionally goes for the False Gramma as well, but rarely bothers the Clownfish.


All the fish are eating normally, but I’m concerned the aggression could get worse as they grow.


I’m considering putting the Strawberry Basslet in an isolation box for a day or two to see whether the other fish settle down, or possibly rehoming some of the damsels.


I’d really appreciate some advice:


  1. Is this normal territorial behaviour for a Strawberry Pygmy Basslet?
  2. Is my tank overcrowded for these fish?
  3. Would removing the Humbugs and Blue Damsel help?
  4. Would you keep the Strawberry Basslet or rehome it?
  5. Is an isolation box a good idea to try?

I want a peaceful community tank and don’t want any of my fish getting injured.


Any advice or personal experience would be appreciated. Thanks!
 
In a 30g tank, you have 5 fish that can show signs of aggression. Those are the damsels and the clowns.

Personally, I would either ditch the blue damsel and one of the humbugs, or get rid of the pair of humbugs.

The basslet is probably defending its home from the aggressive fish listed above.

I think once you remove a couple of these fish, you will be fine!
 
Damsels are very territorial and aggressive fish, once they establish a territory they will defend it to the death. 7 fish in your size tank is very over stocked IMO, and 5 of those fish being damsels (clowns are damsels) and a dottyback to boot, it means that no other fish can be safely added to your tank IMO. As your fish grow, they will get even more aggressive, and they are more so aggressive in small tanks, and your tank is too small for these type of fish. Keep in mind that aggression and stress makes it very easy for disease to set in. I would re-think about your fish list,
 
Last edited:
To many fish, not enough houses. He's defending his cave, cause there people constantly near his cave
 

WHEN REEFING GETS TOUGH, WHAT KEEPS YOU MOST INVESTED?

  • My livestock depends on me, so I keep showing up for them

    Votes: 15 55.6%
  • I look for small signs that things are improving

    Votes: 3 11.1%
  • I want to figure out what’s going wrong

    Votes: 1 3.7%
  • I remind myself that rough stretches will pass...just keep reefing

    Votes: 4 14.8%
  • I lean on other reefers for advice or encouragement

    Votes: 0 0.0%
  • I simplify, step back from tinkering, and give the tank time

    Votes: 2 7.4%
  • Honestly, sometimes I wonder if I want to keep going

    Votes: 2 7.4%
  • Other (Post in the comments)

    Votes: 0 0.0%
Back
Top
Home
Post thread…
Market
What's new