Nutty fish nutter
Tank of the Month!
- Jul 22, 2020
- Reaction score
But you're advising a beginner to do something with a high potential risk.I have been keeping fish for over 45 years and doing this for over 20 years never had a problem. What aquarists do consistently is over analyze things. The best advise is to keep it simple. When we all start out we do what others do or tell us to do. Over time we work things out for ourselves. There are no right or wrong ways of doing things it is what works for you and what you a comfortable with.
If the replacement water is the same temp as the tank water, no potential harm.
"Cold" water added to tank (which might be much colder than the tank, you don't know their source or locality) does come with a risk. If there's a big temp difference, risk of shock and death, and at the very least, stress.
So the simpliest thing for a beginner is to temperature match, to go with the safest course of action that doesn't have the potential to be dangerous.
If your source water is close in temp to your tank and it's a small partial water change, or you're trying to induce spawning in fish, then colder water changes are used, sure. But by people who know what they're doing at that point.