My 1 yr old Pleco is sick . For the past several days he has floated belly up in the tank.He appears to be sucking for air. He is in a 100 gallon tank alomg with a calico koi and bug eyed moor.Each time I attempt to check him, he swims normally to the bottom of the tank , hovers about 1o minutes and then slowly floats back to the top .I have checked the
pH balance of the tank and it is within the normal range and all filters are clean are properly functioning.The other two fish appear to be normal in all their activities.Any suggestions or ideas for me ?
thanks,
KK