Fish Wont Stop Following Their Reflection

  1. Vortexed

    Vortexed Valued Member Member


    So I got my new tank all cycled and problems are being sorted out, and I should get a new fish or two this weekend. However, my 3 fish that I have in the 20 gallon keep "chasing their reflection" on the sides of the tank. Now I thought this was because of boredom, so I added a crocodile skull, a barrel, and some plants to match their natural enviorment and keep them entertained. Well it did, for about half an hour. Then they went back to chasing their reflection.

    How can I make them stop?? I mean, the tank isnt reaching its full potential if all the fish are just on the sides of the tank behind some plants chasing their reflection.. I put my hand infront of the tank to get them away from the sides, but the clever little things just go to the other side of the tank lol :p
  2. APierce

    APierce Well Known Member Member

    What kind of fish are they, certain ones do this a lot! The only way to stop it is to stop the reflection :)
  3. KimberlyG

    KimberlyG Fishlore VIP Member

    They eventually get bored and stop that too when they can never catch themselves. Normal behavior.

  4. OP

    Vortexed Valued Member Member

    Should I just put paper on both sides to stop the reflection?
  5. APierce

    APierce Well Known Member Member

    That might help, you could also put something in the back corner that breaks up their view.
  6. KimberlyG

    KimberlyG Fishlore VIP Member

    I have a background. If your tank is clean, they can see themselves. lol
  7. Aster

    Aster Well Known Member Member

    It sounds like glass surfing, a sign of stress. Were they newly introduced?
  8. Herkimur

    Herkimur Well Known Member Member

    Maybe it's a form of play.
    My minnows did that, too, and they were perfectly healthy.
    When they got sick the behavior stopped.
    Perhaps it's also a sign of health if they play.

    In nature (watching wild fish in creeks when I go camping) they come in packs of 6 or up to 10 and swim up and down the same path, back and forth, all day.
    Always close to the bank where the river is calmer.

    Bigger fish are in the deeper part of the river where current is super strong but those tend to 'hover' in place a lot (trout or sturgeon)

    My profile pic is a sturgeon in one of those fast flowing places.
  9. OP

    Vortexed Valued Member Member

    Yea, few days ago
    Is it mean to put paper so they cant see their reflection?
  10. Aster

    Aster Well Known Member Member

    Give them some time and they should stop doing it, it's not uncommon for fish to glass surf in a new environment. Turning off the lights will help as well.
  11. Danjamesdixon

    Danjamesdixon Well Known Member Member

    Generally, unless you've got strange lighting conditions, it's unlikely they will be able to see their reflection in the glass. What is generally observed from the exterior of an aquarium is Refraction.

    It sounds more like glass surfing.
  12. s

    smee82 Fishlore VIP Member

    What type of fish are they. If they are schooling fish its most likely a sign of stress.
  13. fjh

    fjh Well Known Member Member

    Putting up paper should prevent them seeing their reflection as well, and no it is not mean.

    What type of fish are they? Some fish will do this anyway, even when they aren't new or stressed or anything. My male guppies glass surf 24/7 when there aren't any females present.
  14. S

    S_Fish85 New Member Member

    Possibly. Doesn't hurt to try. But they'll eventually stop anyways. Then they will do it again then stop then do it again then stop. Just just about all my fish do it at some point.
  15. AllieSten

    AllieSten Fishlore VIP Member

    You just posted a couple hours ago that you had 0.25 ammonia in your tank, so it wasn't cycled. And that you didn't have a gravel vac or a way to do the 50% water change recommended.

    My guess is that your fish are stressed out because your tank isn't truly cycled. If you get your water parameters under control and the nitrogen cycle on track, their behavior should settle down.

    I definitely wouldn't add another fish to your tank until you have been fully cycled for a few weeks. You are risking losing your fish.