Sudden Death

Question
Hi, my friend Nicole bought a beta fish in October from Petsmart.  For a while she kept him in one of those beta buddy duplex things (he had a whole one to himself accept for some bamboo and colored gravel).  He also had one of those colored decorations that look like rocks but with a bunch of large round holes (sort of a hidey hole).  A couple weeks ago she moved him and his stuff to a goldfish bowl to give him more space.  She's always fed him dried bloodworms.  They were from Wallmart.  Tonight after she changed his water weird stuff started happening.  (We live in a University dorm and have always used their sink water).  He wasn't very active and he sort of sank to the bottom.  The fins right behind his gills turned from their usual clear and red to white and he started twitching.  He was dead within 5 minutes.  He had always seemed really healthy and active had gulped up all his food just an hour or so before he died. A previous internet search suggested Tuberculosis but we'd really like a second opinion.  Nicole is really torn up about loosing her fish friend.  She wants to get another but nether of us want a repeat of tonight's episode.

Answer
Hi Sarah,
I'm so sorry that your friend loss her little friend.  Bettas will live a long time if we know how to keep them.  Unfortunately, it seems like there is little information on how to keep this beautiful little fish.
Bettas should be kept in 5 gallon tanks, and there water should be around 80-82 degrees.  When bringing home a betta, we all know that the little sadistic cups they are kept in, are not heated, so we put the betta in unheated water, around the temperature he came in.  Then we heat his water slowly, very very slowly, ONE degree every two days as bringing up their temperature too fast could cause death.  Adding a teaspoon of undiluted aquarium salt to his water helps with stress, and parasites.  (One teaspoon to five gallons of water)  In his habitat the betta may live in shallow waters, but he has lots of room to swim.  Small tanks, bowls, vases, and mirrored tanks are all money making machines, and not suited for the betta.  Vendors do not care, as long as they sell.  They are there to make a buck, and this is all that matters to them.  Bettas kept in small containers will get sick, and their lives are cut short.  They are intelligent little beings, and should not be treated this way.  Unfortunately, their are no laws to protect fish, and not much good information on how the betta should be kept.
When kept in bowls their water temperature will fluctuate, and fluctuating water temperatures will be deadly.  Under 80 degree water, the betta is cold, and will get sick.  We must always use a good water conditioner when changing his water such as "Stress Coat," or "Aquaplus."  We also must make sure that we put the betta back into his tank in the same water temperature he was in.  It is very rare that a betta dies suddenly.  He usually shows signs of illness well before he dies.  Since he had no heater, I would think that your water was fluctuating, and this can kill a fish very quickly.  One little drop in temperature is very bad for a fish.  He may also have had internal parasites, but you would have noticed this, as the betta would have shown signs of illness.  He may also have died of heart failure.  It is difficult for me to know exactly what happened to him, as I would have had to make a biopsy.  I feel confident that it has something to do with the water, and his living conditions.  I doubt it was Tuberculosis.  He would have shown symptoms of this disease such as loss of appetite, eyes would have been popped out, he would have remained at the bottom of the tank, sometimes on his side, and he would have had trouble breathing.  You would also have noticed white patches on his body, and his tummy would have shrunk.
Here is some information on bettas, that I hope you will find helpful:
Bettas should have varied diets.  Betta Pellets, Betta Flakes, Daphnia, ( Daphnia is very important has it helps with their digestive system.  Bloodworms, 2-3 times a week as a treat, Glassworms, Plankton Flakes, brine shrimp, and one frozen pea a week.  One day you feed him pellets the next flakes, and so on.  He must be fed in small quantities 2-3 times a day.  Example:  2 pellets for one meal, or 2 flakes for one meal.  Their tummy is the size of his eye, and we must always remember this when feeding them.  One cooked frozen pea a week is a must.  Cook the pea, remove the outer layer, and cut it into tiny pieces.  Feed the pieces one at a time to your betta making sure he eats it, and that it doesn't fall to the bottom of the tank.  On the day you feed him the pea, feed him nothing else.  This is so he cleans out his system, and avoids Swim Bladder Disease.  The Betta is prone to this disease which begins with constipation, so it is better to avoid it.
I hope this information helps, and if you have any other questions, please do not hesitate to write me.  I have bred bettas, love them, and know how attached we are to them.
Lynda