Delta Tail Betta Acting Strange

Question
Hi Lauren~
I have a Delta Tailed Betta, and have had him for 2 years.  Originally, I housed him in a 1 1/2 gal tank with a mini filter in it.  I preformed water changes every 2 weeks until I found out that I should be doing the water changes more often.  The filter cartridge gets changed every month, and for the past year I have been doing 3/4 water changes weekly (I leave him in the tank and keep only enough water in it for him to be in while I put new treated water in).

About 2 months ago, Booger (yes that's his name) got very sick.  It was the one time that I decided to take him out of his tank to do a good cleaning, and he jumped out of the shrimp net and onto the carpeting!  When I got him off the carpet, he flipped out of my hands back onto the carpet!  I finally got him back into water, and waited to see if he was going to make it after all the drama.  He did, but he was swimming sideways and staying at the top of his tank.  

He did this behavior for several weeks, and hardly ate.  During the past two weeks, he has been hiding in either his cave or in the live plants.  He is no longer doing the floating sideways thing or staying at the top of the tank.  He comes out to eat and is swimming around for a little bit after he eats.  I have recently moved him into a 3 gal tank, along with his mini filter, his old gravel (I figured that it would have good bacteria in it) and he has a waterproof heating pad to keep his tank water at 80 degrees (I monitor it throughout the day to be sure it isnt getting too warm, and the heating pad seems to work just well when wrapped around the back outside his tank between the tank and the wall) and his halogen light is defused with cheese cloth (to make it less bright for him but still allow him "daylight", as I live in a very dark apartment with no sunlight.  The light clips onto the shelving unit and extends 5" above his tank, with the cheesecloth covering that portion of the top of his tank).  His water is Crystal Geyser Spring water and I test it with a strip test before I heat some up in the microwave to get it to 80 degrees).  He eats Betta flakes, and defrosted bloodworms once a week.  He also has "new" roommates, 3 glass shrimp.  He pays them no mind, they even sleep in his cave with him and he doesn't seem to care.

My concern is that his coloring has faded, and he isn't as active as he used to be.  He isn't showing any visual signs of ick or of velvet, though I have noticed that he looks to have faded the most under his mouth.  I have added a few grains of aquarium salt to his water, and done partial water changes every other day because I thought maybe his water had been dirty and made him sick.  Two of his roommates have died (I think of natural causes because they were intact without any obvious signs of being attacked.  I had them for about a year.  They had been moved from my 20 gal tank, because I got a clown loach to eat the snails in that tank, and I was afraid that she would eat the glass shrimp too).  So now he only has one glass shrimp living with him very clean water, a bigger shallow tank (his other one was a taller hexagon plastic tank, this 3 gal tank is a shorter hexagon glass tank my neighbor gave me) he has live ferns in the tank, fine gravel, a few small snails (about 1/4 in each).  He eats 2-3 times a day, and the shrimp eats whatever he doesnt.  I have tried to give him a pea, but he refused to eat it! (my barbs LOVE peas and get them at least 2 times a week, so when I give the Barbs peas, I try to give some to Booger too.  He just looks at me and goes back to his cave.

I know that Bettas don't have long lives, but I figured I would have him for 3 or 4 yrs.  Now Im thinking that I may not be that lucky.

Any ideas on what I am doing wrong, or what I can do to help Booger get back his "groove"?  I have another Betta, Pretty Boy Floyd, and he has pretty much the same living conditions except his tank is only 2 gals and has 3 ghost shrimp roommates.  He is a baby, a very small crowntail betta.  And he is very active.  Booger looks like an old man compared to PB. It makes me sad to see him resting all the time and not enjoying life.

Answer
Hello,
You seem to be taking good care of Booger.  He may be getting older.  We never know what age they are when we buy them.  If his tummy was swollen I would think Swim Bladder Disease, and treat him with an antibiotic such as "Tetracycline" or "Furan-2"  Well kept bettas live up to 7 years when bought young.  The best I can do is to give you more information on the Betta.  We really don't have much to go on.  Have you checked his water for ammonia, or nitrites?  They should be zero.  In a three gallon tank, I would prefer to change his water every week with a good water conditioner.  If he has ammonia, or nitrites in his tank, this could be deadly.  It is very important that you check this first before using antibiotics.
Since he refuses to eat the pea, feed him Daphnia.  Daphnia is very good, and helps their digestive system.  Vary his diet as much as you can.  Make sure his water isn't fluctuating.  Fluctuating water is very bad for fish.  A thermostat would be better to ensure that his water is always the same temperature.  Temperature that goes down 2 degrees may be deadly.  I'm not sure I understand your setup, but do know that heating water with lamps is not good.  The water is warmer at the top than the bottom.  His water should be 80 degrees, and stable.
Feeding a Betta 2-3 times a day is good, but in small amounts.  Two pellets, or two flakes for one meal.  Their tummy is the size of their eye, and we must always remember this when feeding them.  Bettas should have a variation in food.  Some of the food they like are Betta pellets, Plankton flakes, Bloodworms, Glassworms, Mealworms, Brine shrimp, and of course Daphnia.
The best way to keep a betta is in a 5 gallon heated tank.  In his habitat, the water may be shallow but they have lots of room to swim.  When heating tanks for a betta, we must do this very very slowly.  One degree every two days.  Sadly, most vendors do not give good information on Bettas, and many other fish.  They are there to make a buck, and this is all that counts for them.  Many bettas are kept in small containers, tanks, and vases.  These bettas will get sick, and their lives are cut short.
For now check your water chemistry.  Check all the levels...Ammonia, Nitrites, Nitrates, and the PH.  Please write back to me with the results.  If you suspect Swim Bladder Disease, you will see that his tummy is swollen.  His tummy is just below his chin, but before medicating, we must be sure of his water chemistry.  If his water chemistry is off, then you have found the problem.  
I hope this will help
Lynda