Most grey water contains some quantity of sodium and chloride compounds from soaps and detergent. This can build up in the soil and damage your plants if you overuse the grey water. Minimize the risk by alternating between grey water and fresh water, or by spreading the grey water across a large area with a drip irrigation system. Grey water contains beneficial chemicals as well, such as nitrogen and phosphorus. You may want to reduce your fertilizer use to avoid excess phosphorus. Young plants and plants in small containers are more susceptible to sodium buildup. Direct the grey water to mature plants instead.  Never use grey water on vegetables that come into direct contact with the soil, or on leafy green edible plants. Fruit tree regulations vary by region. California limits grey water use to citrus and nut trees. Queensland allows grey water for all fruit trees, as long as irrigation stops two weeks before picking, and no fruit is picked up off the ground.  Grey water tends to raise soil pH. Keep it away from plants that prefer acidic soil, such as rhododendrons, ferns, and azaleas. Ideally, the grey water should travel through subsurface irrigation lines. Surface irrigation is fine as long as humans and pets minimize contact with the soil, and the grey water drains rapidly. Since it contains bacteria, never allow the water to form puddles on the surface or runoff into a storm drain or water supply. Do not use a sprinkler system, as this sends the water into the air. If you see "burns" at the edge of leaves, a pale bleached color in new leaf growth, dying branches, or stunted growth, switch back to fresh water. The harmful compounds can build up over time, so continue to check regularly. You can reduce the risk of damage and help treat existing damage with the following practices:  Keep the soil slightly damp so the sodium drains through.  Lower soil pH with soil additions until the pH is around 7. Add 2 inches (5 cm) mulch to the soil surface.

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Write a summary of the previous text in Chinese:
从小处做起。 慎选要用灰水灌溉的植物。 不要让水流到地面。 留意植物受到损害的迹象。 缓解有害影响。