why are my daughters goldfish 'gulping' at the surface of the water in their tank?
Hello I'm Dr. Bob. Usually surface gulping is caused by the lack of oxygen in the water. If you have not changed their water lately, the ammonia and bacterial byproducts can build up and cause the oxygen content of the water to decrease. If you have an aerator, this helps, up to a point, but cleaning the aquarium is the best way to get rid of the bacterial build up and increase the oxygen content. Overfeeding is also usually part of the problem. Be sure they are sparsely fed. Fish are better off being a bit hungry.When you change the water, only change 1/6 th of the water at a time, and be sure to use a de-chlorinator solution when you do.Best regards.
35 years in practice