Hi, I added my fourth and final goldfish to my 55g yesterday. He seems
very happy and sooo at home. My Ryukin has behaved very oddly since
his introduction. She is just sitting in the middle of the tank. She
is doing this of her own accord as fins look like they are moving
normally. She is eating well and will venture over to the usual corner
when I add the food. She usually spends most of her time in the
planted area but now she is just out in the middle of the tank. I did
a water check and the water is perfect. Cycle finished on Monday, such
joy. She has chased the new fish once or twice when he has got too
near but she returns back to the center of the tank after. It really
is like she is sulking but she has been doing this for about 24 hours
now and I'm starting to get that 'worrying feeling'.

Should I worry? The other 3 fish are so happy. Could it be that the
end of the tank she normally hangs out in is too crowded for her? Was
thinking of getting some live plants and planting the other end so that
they use the 'whole' tank a bit more.

Any advice greatly recieved.
Mellie