When to test???

[mcdeali]

Do you do an ammonia and nitrite test before or after you do a water change?

This is probably a dumb question but I don't have a test kit and one of the few knowledgable fish store guys said he would test it for me and in front of me for free.

 

[daveedka]

Depending on the situation: I would say after.
With a home test kit during things like a fishy cycle, I usually test before and after so I can see how much my water change helped. If you have to take the water to the lfs, you would want to test it after a water change so you know what conditions your fish are living in. Once your cycle is complete unless something major changes ammonia and nitrite testing becomes less frequent and necessary.

 

[happychem]

I would say before the water change, so that you can see what kind of buildup has happened over the elapsed time since your last change. If you don't know your tank very well, it could be useful to do both, that way you know how much improvement to expect from an x% water change.

After the tank's cycled, there's very little need to check ammonia and nitrite unless you've added more fish or something's changed that may have upset the balance. At that stage NO3 is far more indicative.

 

[mcdeali]

thank you ...i will take a before and after sample with me