Doing a 20% water change...

[ToWnPrEp]

Or is the tap water ok with the 20% change?

 

[pendragon]

No, the tap water is not okay. You must always dechlorinate tap water before adding it to the tank.

pendragon!

 

[Inchworm]

Hi ToWnPrEp

Always dechlorinate tap water before adding it to your tank.

The chlorine is there to kill bacteria that might be harmful to humans, but it will also kill the beneficial bacteria you are trying to cultivate in your tank.

If you are not sure whether your local water authority uses chlorine or chloramine to do the job, use one that removes both.

 

[pendragon]

but it will also kill the beneficial bacteria you are trying to cultivate in your tank.

...as well as your fishes' gill tissue.

pendragon!

 

[Tempestuousfury]

Regardless of how much water you change, always dechlorinate the water. You don't always have to use chemicals, though, but it's easier.