What does ca va bi en merci?

"Ça va?" is an informal pleasantry, roughly meaning "How's it going?"

One reply is simply, "Ça va." for "It's going." (this has less of a negative meaning in the French than the English equivalent--in the French, it's meant as "Okay.")

So your phrase, 'Ça va aussi, merci,' could be translated to mean, 'I'm okay, too, thanks."