I've recently got a pair of goldfish and put them in a bowl. I'm trying to keep them happy by feeding them all the natural thing they eat in the wild (and they are loving it too).

It has been 4 ~ 5 days and things were going fine, until I got them a little bulb to keep them warm and light up the bowl a bit. But, after around 2 hours from the moment I switched the bulb ON, the fish would come to the top, pop their mouth out of the water surface a bit, and gulp air, then they would go down and release bubbles.

Initially, I thought, that due to low oxygen and high impurity rate in the bowl, they are gulping air from the top and immediately changed the water. But, again when I put the bulb back on, they started coming to the top releasing bubbles.

I don't know if they are doing this to get more heat (as it's a bit cold these days here) or they are just feeling good doing this... Please help me as soon as possible... :(

Edit 1:

  • Both of my fish are 2.5 inch (7.5 cm).

  • I change their water every 3 days.

  • When the bulb is removed they discontinue this behaviour.

  • What are you feeding them?
    – Spidercat
    Commented Jan 11, 2015 at 18:04
  • I'm feeding them with pellet food and peas one day, then next day I give them blood worms and repeat the same.
    – 0x550x42
    Commented Jan 11, 2015 at 18:05
  • Is it the brightness that cause them to be like this? If its ok, U can try giving them heat using a tank heater instead of bulb. U can usually purchase them from pet stores that sells fishes.
    – Win.T
    Commented Jan 12, 2015 at 3:50
  • I will consider getting a heater but I also want to know the reason for such a behaviour cuz if they are liking the bulb I wouldn't want to change that..
    – 0x550x42
    Commented Jan 12, 2015 at 4:19
  • Gulping air is not a good thing in fish, so I would suggest removing or turning off the bulb. How long between changing the water and turning the bulb on (is it always 2 hours)? How long does it take for the fish to start gulping air? Did you do any tests to see if the PH, nitrates, nitrites, and ammonia where at acceptable levels when this behavior starts instead of just changing the water? Do you do a 25-30% water change? Have you change the temperature of the water when the fish start gulping air? Commented Jan 15, 2015 at 4:32

1 Answer 1


I just went to the pet store and got an air pump and an air stone and installed them to my fish bowl. I observed that this solved 3 things :-

  • Air bubbles trap some of the dissolved impurities and release them at the surface.

  • Replenishing oxygen level in water by increasing the surface area of water in contact with air.

  • Generating disturbance at water surface, generating little waves, and continuously moving the inside water which most fishes are fond of.

I also observed that my fishes are not struggling to breathe anymore. :D


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