Hello. I have a blue dwarf gourami which i had for close to 8 months. He has been acting funny lately. He used to swim around and always look for food. However for the past few days, he's just been idleing on the top of the surface not moving at all. He then starts to sink and then he just swims back up for some air and stays there. Also it seems like he's only trying to move the top part of his body and doesnt kick too much with the tail. He does seem alittle discolored. I have not done a water change yet in like a week. The ph seems fine. I'm not sure what it is. Please help!