Feeder systems consist of a small pump that injects small amounts of chlorine (usually) into the incoming water. The water must then be held for a short period of time to allow the hydrogen sulfide to precipitate out of the water. This tank should be designed in such a manner that the water that enters it will mix thoroughly with the water in the tank, to assure complete reaction. The water then should pass through a filter to remove both the precipitated matter and the chlorine remaining in the water. You should be aware, however, that whenever you mix chlorine with organic materials (remember where hydrogen sulfide come from!), the chances are very high that trihalomethanes (possible cancer causing cragginess) will be formed. Also, feeder maintenance is high, you should be prepared to "play" with the unit frequently.