My Male Beta Fish

Question
He keeps floating on the top, like he's dead. I've had many before him and never saw this.  I read up a little and came to the conclusion it may be too cold in this room.  I am taking him (and his tank) downstairs where it is much warmer.  See what happens.  If you think it may be something else, I'm all ears.  I cleaned his tank not too long ago and I always use bottled spring water. Any suggestions would be appreciated.  Thank you.

Answer
Hello,
Using bottled water is not good for fish.  Tap water has all the minerals fish need to survive.  If you do change his water to tap water do this slowly...first change 1/4 to tap water, then next time you clean, change 1/2 and so on.  A betta should be in 78 - 80 degree water.   He is a tropical fish, and is cold under this temperature, and will get sick.  Never heat his water too fast...when heating a tank, do this  very very slowly..one degree every two days.   If heated too quickly would kill your betta.  
He could have swim bladder disease which is caused by poor diet, and constipation.
Try the pea treatment mentioned below, and if that doesn't work you will have to medicate.  "Kanamycin" is the best medication for this disease.  If you cannot find it, try tetracycline, or furan 2.  Be sure it is Swim Bladder before medicating.  Signs are a swollen tummy, betta floating at top or bottom of tank...no waste in tank.

He could very well be having a reaction to the cold water.

Here is some information on the Betta, and how he should be kept in order to stay healthy:
A betta needs 5 gallons of water to be healthy, and happy.  
In their habitat the betta may live in shallow waters, but they have lots of room to swim.  
Keeping Bettas in small bowls, containers, vases etc, is cruel.  The Betta is one of the most mistreated fish on the market.
They need a heated tank.  Temperature should be 78-80 degrees.  They are tropical fish, and are cold under this temperature.  Cold bettas get sick, are miserable, and live unhappy lives. ( Always remember  when heating a tank, do this very very slowly..1 (one) degree every two days, as bringing up the temperature too fast would kill your Betta.)  The temperature should always be stable.  Fluctuating temperature is very bad for bettas, and any other fish.  
They should have a silk plant in their tanks, so that they can rest on the leaves  They also need a little tunnel or some knick knack that they can go through.   One teaspoon to five gallons of diluted aquarium salt may be added to his water, when a Betta is well.  
Aquarium salt helps them with stress, and helps with parasites.  However if a Betta is showing signs of a swollen tummy, salt should not be used.
They need a varied diet. This is very important.  Betta pellets one day, Betta Flakes the next, Daphnia the next, and bloodworms should be given once a week as a treat.
He should be given one well cooked frozen cooked pea a week, and on the day you give him the pea, he should fast.    
A betta is prone to constipation, and constipation leads to Swim Bladder Disease.  A frozen cooked pea a week keeps them from getting constipated.  Always remove the outer layer of the pea, and cut it into small pieces feeding it to your betta one piece at a time.
They should have 2-3 small meals a day, and not one big meal.  We must remember that their tummy is the size of their eye.
Example:  2 pellets for one meal.
Water changes are very important.  Water changes must be made every week without fail with a good water conditioner such as Aqua Safe or Stress Coat.  There is also a conditioner made especially for bettas.   Never put two bettas in the same tank, they will kill each other...male or female.  The Betta male is a loner.  Females can be kept together in a big enough tank.
When treated well, a betta can live up to 8 years, if you buy him when he is very young.  (Unfortunately we do not know their age when we buy them at the Pet Store which is why some bettas die two or three years after we have bought them.
He's an intelligent little fish, and should be treated with kindness.
Too many vendors know nothing about the betta, and don't care...so don't give good information on how to keep them.
They are there to sell, and will say anything just to make a buck.  They send you home with your bought betta, telling you a small bowl is perfect, and bloodworms!  The poor customer thinks he has everything he/she needs, and then the fish gets sick, money is spent to cure him, and eventually the fish dies.   
This turns my stomach over.  Unfortunately there are no laws to protect fish.  
Bettas kept in small bowls, one gallon tanks, and vases, will get sick, and are very hard to cure in such little water.  They end up dying, and
that hurts the person who has grown so attached to them.  They don't deserve to be treated this way.
This is how a Betta should be treated.  If treated this way, you will have your friend for a long long time.  I have bred them, love them, and know what is good for them.
Lynda