Only 1% of all water on our planet is available for human use, 97% lies in the seas and oceans, 2% remains frozen in glacial ice. As more and more regions around the world are experiencing extended periods of drought, increased pollution and salination of acquifers, the question of how water is collected, uses and reused, polluted and cleaned up by growers becomes increasingly important. Water costs money and so does its conservation and recycling. The first sensible thing for growers to do is to examine current water practices; group together plants that have similar water requirements; ensure that substrates have a good balance between drainage and water holding capacity; test pH, salt levels and bicarbonates; check that the irrigation system is watering the plants uniformily. After checking these factors, consider the benefits of upgrading or installing new irrigation systems. Overhead irrigation and hand watering are the most wasteful. Drip irrigation provides greater control over the amount of water applied and subirrigation (ebb & flow benches, flood floors, troughs and capillary matting) offer much better solutions that reduce waste water and permit its reuse. A good idea is to install storage tanks and retention ponds to capture rainwater and to hold waste water. Rainwater can also be collected from roof gutters. It is then necessary to evaluate the cost benefits for different systems against different crops, the cost of the technology and the payback from the investment (reduced water usage and cost, compliance with regulations, production quality, reduced labour costs etc.). Finally growers need to consider how water use can be integrated with environmental control systema; closed systems that allow the recycling of all waste water, mixed with clean water and disinfected as moves round which also reduce the cost of fertilizer use. Jennifer D White, "GrowerTalks" www.growertalks.com