Aqua Kem Blue is a powerful and easy to use additive for waste holding tanks. It has a pine scent and can be used in Cassette Toilets as well as Porta Pottis. Its formula is derived not only to supress unpleasant smells and reduce gas build-up, but also to break down solids and toilet tissue. To use, simply pour 150ml into a 20Lt waste tank. Add 2-3Lt of water to ensure optimum performance. Thetford recommends refreshing every 4-5 days.