sounds like some dirty stale water i smoke out my bong alot and have never gotten the slightest sick you need fresh water every time you use it( change daily) take smaller slower hits so your lungs arent busting out from too much smoke, i had a friend who thought he could clear a entire bowl 1 hit and he threw up in my driveway and almost passed out from all the excess smoke just take it easy and make sure water is clean