water change question

Yes, as close as you can get it, is best.
 
If the temps to high you can replace the water with very little at a time to SLOWLY change the water temp. But you can't just dump freezing cold water in.
 
Just adjust the cold and hot taps to the correct temp.
 
You should try to avoid using hot water from the tap as I think I've heard that it puts in more copper from the heated pipes and this can be bad especially if you have shrimps or snails.
 
right, that is true for sensitive inverts. It is recommended by avid shrimp breeders NEVER to use warm water from the tap, only the cold side. But if fish are your priority (and they are mine), it is better to add water as near tank temp as possible. If you're concerned about copper from pipes, just leave the warm water running for awhile. That should allow most of the copper that has built up in a closed tap to run out.
 
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