top 3 causes of fish deaths:
1. tangs in tanks that are too small
2. lung cancer
3. carpet surfing
you be the judge.
seriously though, I don't think you'll have a problem unless you are just carelessy blowing the smoke into the tank. my dad was a smoker and had a successful tank for 20+ years without a problem. I hope that you at least try to keep the house ventilated enough so the air in the house is breathable, right? if so, I don't think you'll have a problem.