Why are my goldfish acting strange?

Goldfish acting very strange?

• I bought 2 little gold fish, one of them is acting normal, but the other one is opening his mouth open wide really quick and shutting it, he swims sideways near the ground as if a ...show more

• Answer:

  I think the goldfish should be fine because when it is sucking on the rocks, it is looking for food hidden in the rocks, maybe it is hungry and the fact that it is opening its mouth is normal too, it must be hungry, if you are near the tank and it can see you then it could be hungry. But it could also be there is not enough pH in the water also the water must be cold, the goldfish love cold water. As far as im concerned the swimming part is normal, my fish does that sometimes, they could be just playing around.