a few weeks ago i use a bit of copperesafe in the tank and last week i did a water change and since i did put activated carbon in the tank .....should i do a water change to my tank seeing how it needs one this week before i put the snail im gonna get into it ...and if so how much of a water change should i do ? thanks a lot

another thing is i heard a snail needs a bit of harder water and mine is a bit softer then what is perfect ...someone said to use baking soda to harden it ...should i do this before i bring home my new baby ?