Fish Gathering At Top Of Tank

  1. c

    cody11 Valued Member Member

    Hi all,

    I have a 20 gal tank with tetras. I noticed they are gathering at top of tank. They were swimming around all day. Why would they be doing that and is there something I should do. Thanks
     
  2. bryangar

    bryangar Well Known Member Member

    Seeing as you don’t have any info on your profile, can you answer some questions?

    Was the tank cycled?
    How long has it been up?
    What are your parameters?
    How many fish and what kind are in there?
    What do you do for maintenance? Water changes? How much? How often?
    Is it filtered? Heated?
     
  3. Adriifu

    Adriifu Well Known Member Member

    Please answer the questions listed above as well as my own.

    Is there a lot of surface agitation?
    What size and temperature is the tank?
     


  4. OP
    OP
    c

    cody11 Valued Member Member

    The fish have been in the tank for two days. They are all skirt tetras in a 20 gal tank. there are 10. What I did was put an old filter from the 20 gal from before into the 20 gal with the water from the 10 gal plus the new water. I have done this before and it cycled fine.
     
  5. OP
    OP
    c

    cody11 Valued Member Member

    20gal tank 78degrees. I don't know what you mean by surface agitation?
     
  6. Adriifu

    Adriifu Well Known Member Member

    What are the water parameters (ammonia, nitrite, nitrate)?
    Surface agitation is water movement at the surface of the tank. Does the water move a lot, does it flow slowly, or does it not move at all?
    Are the fish breathing heavily?
    Does it seem as though they're gasping for air?
    Do you know what the nitrogen cycle is?

    I would suggest adding a couple air stones to the tank. This will increase surface agitation.
     


  7. OP
    OP
    c

    cody11 Valued Member Member

    Oh my just looked in the tank and everyone is swimming around again.
     
  8. Adriifu

    Adriifu Well Known Member Member

    Can you at least answer the questions just to make sure they're all right?
     
  9. OP
    OP
    c

    cody11 Valued Member Member

    Sorry it took so long couldn't find the test strip. I tested it is in the harmful stage . should I do a water change?
     
  10. bryangar

    bryangar Well Known Member Member

    You definitely should. That would explain your problem.
     
  11. OP
    OP
    c

    cody11 Valued Member Member

    Will do half a water change. Sound ok?
     
  12. bryangar

    bryangar Well Known Member Member

    It would be a good start. How often do you do water changes? I would recommend you buy the API master kit. It’ll tell you the exact numbers of your parameters.
     
  13. Adriifu

    Adriifu Well Known Member Member

  14. OP
    OP
    c

    cody11 Valued Member Member

  15. finnipper59

    finnipper59 Well Known Member Member

    All gas exchange including oxygen absorption occurs at the surface of the water. Sometimes the air between the lid and the water surface gets low in oxygen. I've discovered that an air pump works wonders. You don't even need an airstone stone on it or put it in the water an long as your filter is moving the water surface around. Just place the tubing ubder the lid. If your water surface isn't moving well, then put an airstone on it and place it underwater. The rising of the bubbles will also cause a rising of water to create surface movement.