Chapin's HydroFeed Fertilizer injector works with sprinklers and direct hose spray applications. It's a great way to conserve water and still have a lush, green, well fed landscape or garden. HydroFeed works differently than a standard hose-end sprayer. It adds water back into the tank as your fertilizer is being pulled out. Because your fertilizer has a higher density than water, it sits on the bottom of the tank. The outlet tube reaches the bottom of the tank so when clean water is being added to the being diluted as it's fed through the outlet tube. This is why the tank turns clear after your fertilizer runs out. Auto-mix system automatically mixes concentrate 1 to 10 oz per gallon. Apply fertilizers easily with professional results. Designed for use with fertilizer products only. Comes in 1 gallon or 2 gallon.