What is Water Hardness?by | 10-11-2013 23:09 |
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Water hardness is a measurement of the concentration of divalent metal ions such as calcium, magnesium, iron, zinc etc, present in water. It is usually acquired as rainwater percolates through rock. Water hardness is mostly related to calcium and magnesium salts and other metals in traces. Types of water hardness a) Permanent hardness: Permanent hardness measures the ions such as nitrates, sulphates, and chlorides etc, that are not removed by boiling. b) Temporary hardness:This form of hardness is also called carbonate hardness or temporary hardness because it can be precipitated and removed by boiling the water which is why lime-scale forms in kettles and showerheads. Effects of water hardness: Water hardness affects fish health because it influences osmoregulation. Having open systems, fish are affected by the concentration of the surrounding water. Against the continuous movement of water into or out of the body, fish have to maintain a constant internal body fluid concentration _ a process called osmoregulation. The greater the difference in concentration between the fish's body fluids and the surrounding water _the greater the osmotic effect. As hard water is more concentrated than soft, there will be less difference and therefore less water influx and consequently the fish will not have to work so hard at osmoregulation. Also, some common fish disease treatments are affected by water hardness. |
