Betta heater

Question
hello-
I just bought a heater for my betta. This is the first heater I have owned, so I don't know much about heaters. The only problem is, I have a heater that automatically sets the temperature
to 75 degrees. But I have 65 degree water now, and I'm afraid that would be too drastic of a change. I tried putting him in the heated tank, but he opened his mouth really wide and fluttered up and down, so I moved him back. The heater takes 2 days to fully heat up, should I plug it in with him in the tank? (He is in his new tank, but the heater isn't plugged in.) Will that be better? If not, what should I do?
~Ann

Answer
Hi Bella,
You must heat the betta's water very very slowly.  He must have time to get use to the right temperature.  The water should be heated one degree every two days.  Bringing up the temperature too quickly would be deadly.  I do not know how automatic heaters work.  i have adjustable ones on all my tanks.
Two days to bring the temperature from 65 to 75 is much too fast, you could lose your betta.  65 degrees is too low for a betta.  You must bring his water up to 80-82 degrees slowly.  He is a tropical fish, and needs warm water.
There are adjustable heaters on the market for all sizes of tanks.  Aquaclear adjustable heaters are available at your pet store, and if they do not have one, they may order one for you.
I hope this helps.
Lynda