I run the water out of the tap the same temp (just a touch warmer) as the tanks with the NovAqua+ in the gallon jugs and go into the tanks and drain the water and by the time I have them drained and cleaned the water is the right temperature (not more than a little while) and I have not had a problem with my water unless I happen to have a
nitrate problem because of the farming around here and then I buy gallons of Spring Water and heat a bit of it in the microwave and pour it back into the jug to warm it a bit to the temp of the tank and use it directly. I used to put the water out overnight and let it sit but found that it got colder this way and now just do it the way I described and the bettas and other fish do not complain any.
Just to be on the safe side when I first did this I tested for
chlorine in the jugs and it was 0 so I know that it does instantly remove the chlorine and so I feel safe doing this.
Rose