Joe G

I herd if you let tap water stand for 24 hrs, it is then safe to add to fish tank without harming fish. Is that true ??

czarben

Not if there's chlorine added to your tap water. That needs to be neutralized somehow.

chickadee

No not necessarily because the chlorine is not necessarily the only chemical added to the water and the others may be just as harmful. I would not depend on the chlorine not being chloramine during the summer months besides as many of the towns of any size convert to chloramine during the summer months and it is much more dangerous than the chlorine.

I would never consider putting untreated tap water into a tank.

Rose

Butterfly

If Chlorine is the only chemical your water co. is adding to your water you can let it set for 24hrs and it will gas out. I have done this before. HOWEVER...... Most water companies add other stuff and will do so without warning so unless you know for sure what they are adding or are using water from a well it's best to be safe and use dechlor which takes care of chlorine and chloramines everytime.
Carol