Hi, I'm fairly new to the goldfish world but I have 3 small goldfish in my tank, it's a 30L Biorb. The tank's been running for about 2 months now with no problem at all and only change the filtration system as instructed by the Biorb guide. They live from fish food flakes and I have had no problems with them at all so far. However in the last couple of weeks, I've noticed that my lionhead (the other two are Orandas) has started floating at the surface the correct way up. The first time i saw him it scared the22 out of me but as soon as I moved towards the tank he swam off. I have seen him do it about 5 more times since this. He seems to be in no pain or discomfort and seems perfectly happy when he swims off, I just want to know why he is doing this and is it normal for Lionheads?
Thankyou!!