Waterbed Odor Remover and 1 Year Conditioner work best when added together. The odor is described as a mouldy smell. The bed has not been treated for a long long time, or has been infected with dirty water, Either from a top up or fresh fill. Best practice is to drain as much water as you can from the bed and refill with fresh water. Thoroughly flush the filling hose first. Experience shows about a 70% success rate. Price is Delivered