hi i have 2 oranda's 2 inch both . in a 40L tank . i do water change every sunday . i have hade them for almost 4 months . but from the time i have put them in my than they were suffering from swim bladder i gave them a treatment of peas and lots of green vegetables . and there became good .but from that time i have noticed that they anr not so active . i have an air pump but still they remain on the top of the tank and some time they just sit down on the surface of the tank .. but when they see me they start swimming again . what should i do? do the have any Disease.. please let me know . m worried ..