Sudden death...what the heck?

[Kiku]

My betta has been happily living in his 2 gallon hex tank for about a month with no issues. He'd just been getting over fin rot and his tail had healed exceedingly well! His tail was still slightly ragged, but definitely on the mend. Last night he was looking a little pale, but nothing very unusual. I figured I should just closely monitor his appearance. Well, I woke up and he was dead ;_; What could it have been?

His tank was heated at 80 degrees.
Decor included two silk realistic plants, gravel, and his thermometer.
I use seachem prime dechlorinator.
I performed 100% water changes every other day. (monday, wednesday, friday, etc)
He's always been really energetic and eating well. No symptoms whatsoever until last night, and then death by morning.

[cjayBetta]

I was told my OFL that you should only do 1 100% and 1 50% water changes a week with a 2g tank. Maybe you cleaned the water too much?

[allilovesherbetta]

some times bettas get stunned when u clean out there whole tank... next time u should pour some of his old tank water in the new to make him feel comfortable.

[dramaqueen]

This is an 8 month old thread.Please check dates.