Are my fish getting enough oxygen? 20 Gallon Tank

  1. OT4

    OT4 Member Member

    I have a 20 gallon tank. I don't have any air pumps.
    Recently, it's been hit where I live, so my tank has been staying around 80 degrees. I know that the warmer the water, the less oxygen it can hold. My filter is a Grreat value hob filter, with a 90gph rating. It creates a little waterfall. I have 5 guppies. Do they get enough oxygen? They don't go to the surface and gulp air, but I still don't want to not give them enough air.
  2. Coradee

    Coradee Moderator Moderator Member

    As long as the filter flow is breaking the surface of the water then it's oxygenating the water.
    If the fish were struggling you'd see them hanging near the surface so it sounds to me like they're doing fine :)
  3. OP

    OT4 Member Member

    They do stay mostly near the surface, but not above it to gulp air. But they also go down a lot. So thanks, glad they're getting what they need.