Why tank water changes so quickly?

Question
My grandson has a beautiful reddish-orange betta and have had it for alittle over a year.  It is by itself in a 2 and 1/2 gallon tank with no filter.  I try to change the water every 2-3 days and use the water from the tap.  I had used filtered water but the fish seems to thrive as well in my tap water.  Someone told me it was a female for they discovered eggs when cleaning. Not sure if this is correct or not.  

I have noticed that after I change and clean the water, the fish tends to head for a corner, stick the tip of his nose area (I think it is a nose area)up above water and just hang there for hours and hours; and doesn't eat either.  Maybe it goes into shock, don't know but I am interested in why, and also why the water gets so cloudy with bubbly foam on top; nasty looking. Every 2 days it is in that condition.  What is wrong?

Answer
Hi Joyce,
 Your grandson's fish is definitely a male and the foamy bubbly thing on top of the water is his nest.  Bettas are bubble nesters.  The male makes a nest of bubbles and puts the eggs from the female into the nest where they get lots of oxygen to develop properly.   Everytime you clean it out, he feels the need to build it back again -- male bettas are eternally hopeful and optimistic that a female might come by any day now :)

-- Ron
  rcoleman@cichlidresearch.com
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