Betta Fish and their tanks?

[AlinaElvis]

I have 3 betta fish now (one passed away, which was obvious because he was not eating.) The one I got from a great pet store has been with me for 6 months, while the others, from another pet store aren't close to being his size or living as long. The one thing I noticed with the tank of the one that passed away, was his tank would get cloudy after 2 days of cleaning it, and the water looked as if it was thickened, with bubbles on top. And the same is happening with one of my other fish now. Do you know why this is happening? When I clean their tanks, I clean it very well, also putting a betta fish chemical to make tap water healthy for them. I realize I should not go to that pet store and get the bettas, but I do anyways.Could it possibly be chemicals in the rocks? the fish tank all together? or could they have diseases? Thank you (although my question probably doesnt make alot of sense)

 

[Electra]

the bubbles sound like he has been practising making a bubble nest about the water though it happened in mine but that was because i had to do a large water change when i put him in quarantine everything is fine now, I try to avoid large pet stores and go to local ones they normally have better stock and more experience.

 

[Betta lover]

I own 4 bettas currently. Have you been rinsing the rocks thoroughly with hot water? This could be the case- bacteria can form in the rocks/gravel. Get a filter- If you do not already have one. Only use the correct amount of chemical remover- overdosing can seriously hrt the fish. The thickened water- go to bettatalk.com- it will give you lots of great tips for cleaning water. Good luck!