My bf's betta is usually a very active little guy who never stops swimming, ever, unless it's after we turn out the light. So it's a little bit worrying that lately all we've seen him do much of is sleep in the corner.
Here are some more details which cause me suspicion:
1) Four days ago he was moved from his old 14L tank to a 29 Litre tank. All his old water was siphoned from the old tank to the new tank and he still has the same filter and plants, but the gravel is new. Stress-Zyme and Stress-Coat were added after the shift.
2) During and after the move the temperature in the tank dropped to about 25 degrees for a day before the heater was turned up more. He is used to 29 degree water.
3) He lives on top of the entertainment unit, which probably wouldn't be a problem if not for our flatmate who has lately been staying up playing first-person shooting games at high volume until 3 am. I bet none of the fish have had quality sleep time for the last week.
I have checked him for any torn fins or other signs of illness, but so far all we can tell is that he's sleeping a lot.
Could any or all of the above be the cause? Is there something we can do to perk him up a little? Fortunately, our flatmate has now finished his game and hopefully won't be keeping the fish up at stupid hours of the morning for a while now. We are also looking into moving the tank but there's not really anywhere else for it at the moment. Thanks for any help.