In early spring of 2006 my son brought home a betta fish in a bowl from a birthday party. I promptly bought a 2.5 gal aquarium with a filter, light, plants an something to hide under. He thrived. The fish is now well over 3 years old and can't stay upright anymore and has trouble floating up and is very lethargic. I had treated his water with betta remedy which helped him a little but then he became lethargic again. His water temp is always around 75-78 degrees, his water is treated with drops to balance ph and he gets betta fish flakes. Before he got "sick" he also received frozen bloodworms every 3 days. He is fed once a day. I clean his tank completely about every 8 weeks and he gets partial water changes in between when the water seems to need it. Is there anything else I can do or is he just coming to the end of his natural life span?