blue betta fish acting lethargic

Question
QUESTION: I just got Murray 2.5 weeks ago, and he is the only fish in the tank.  He may be about 6 months old.  He (if the male is blue) is in a large round glass tank with gravel at the bottom.  I change the water every 5 days with Brita water filter water at room temp.  The last change was Saturday.  I put the gravel through a strainer and wash it good and completely wash the bowl.  On Sunday I saw a lot of tiny water bubbles at the top of the water.  He is not as playful as he was and spends more time at the bottom doing nothing.  I had a thought that there might have been some residue from Icy Hot that I have been applying to myself.  I washed my hands good and just changed the water again with new food.  What do you think?  Is there something else I should do?

ANSWER: Hi Christine:  lethargy is a sign of an illness in betta. I would treat him with a dose or two of triple sulfate. Betta fish respond better to antibiotics.  He may just be bored... but I am always concerned with betta who's behavior changes suddenly without a reason... dave

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QUESTION: Dave, my friend will go to the pet store as I am on crutches.  Is it possible that residue for the Icy Hot salve could have upset the balance of the water.  What causes them to make those bubbles?  Since I changed the water 2 hours ago,  I am not seeing new bubbles.  Thank you.

Answer
It is possible that the icy-hot has had an effect.  The bubbles on the top of the water... Betta's make bubble nests it shows that he is happy and content.  The male betta makes the bubble nests and hides the eggs that the female lays in his nest.  He then drives her off and raises the babies until they are about 1/4 to 1/3 inch long and then they go off on their own... that is what the bubbles on the top of the tank mean... dave