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Concentration mg/L CaCO3 | Description |
0 - 75 | soft |
75 - 150 | moderately hard |
150 - 300 | hard |
300 and up | very hard |
Environmental Impact: The most important impact of hardness on fish and other aquatic life appears to be the affect the presence of these ions has on the other more toxic metals such as lead, cadmium, chromium, and zinc. Generally, the harder the water, the lower the toxicity of other metals to aquatic life. In hard water, some of the metal ions form insoluble precipitates and drop out of solution which makes them inavailable for ingestion by the organism. Large amounts of hardness are undesirable mostly for economic or aesthetic reasons. If a stream or river is a drinking water source, hardness can present problems in the water treatment process. Hardness must also be removed before certain industries can use the water. For this reason, the hardness test is one of the most frequent analyses done by facilities that use water.
Click here to view the harmful effects of hard water on water tubing
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