extra water

It should be, just be sure to put it back in with a PH and heater well before your next water change....like maybe 24 hours. I would even double check the SG on it as well just to make sure before you put it in your tank. It isn't consuming trace minerals by itself so I would think it would be ok. Just make sure you cover it up well so that dust and debris doesn't collect in it.
 
Top