Drip Depot sells irrigation kits for gravity systems. We offer two types of kits, Clean water kits and Dirty water kits. Clean water kits are a good choice for cisterns, water barrels or any other water source that does not have cloudy water or particulate matter suspended in solution. Dirty water kits are a good choice for ponds, reservoirs or any water source that may have cloudy water or water that may have a lot of debris. Both kits have filters to filter out the contaminates but the dirty water kits are a bit more tolerant of debris.