Water Tank Filter Comparison Chart
Comparison Chart of Pros and Cons of Rainwater Tank Purification Devices |
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Type of Device |
Pros |
Cons |
1. Pre-TankFilter (Typically a sieve-like device that strains water before it gets to the tank) |
• Stops larger debris from entering the water tank |
• Quickly becomes clogged with debris and requires a lot of cleaning, often involving ladders |
2. First Flush Diverter (A purpose manufactured container of about 20-30 litres in a vertical shape |
. Diverts and discards the first 20 or 30 litres of rainfall down the drain resulting in the dirtiest water being rejected |
. Only filters the small initial quantity of rainfall. Can become blocked itself (the chamber slowly drains after rain event) |
3. Waterboy |
• Gathers water from just below the surface of the water level giving much cleaner water, free of sediment from the bottom. Never requires maintenance. Inexpensive. |
• Needs to be installed inside the tank, i.e. water level must be low enough |
4. In-Line Filters (Typically one or two large filters of about 4 litre capacity mounted near the pump or where the water line enters the household) |
. Filter most physical impurities from the water. The first filter usually of a larger ‘micron’ filter and the second a smaller one |
. Require regular monitoring and, depending on general surroundings, become clogged quite quickly resulting in less water pressure and increased pump strain. If badly blocked, can be a definite health hazard and finally filter cost is on-going and can be expensive |
5. UV Light Treatment (A tube shaped device that works by subjecting water passing over it to strong ultra-violet light) |
• Neutralizes any disease organisms present by damaging their DNA. This renders them harmless when consumed |
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6. Under Bench Filters (Smaller, very fine filters that typically target microbes or off tastes) |
• Good for removing smells and tastes from drinking water (Activated charcoal) and disease organisms due to small micron rating. |
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Conclusion All filters are good in some ways (although with the pre-straining devices this is very debatable) however important factors to remember are: Maintenance time and costs. Are you capable of these or is it a job for a plumber and how often will they be required? A minimum of once per year is a given. Do you need to treat all of your water to a very high standard? Remember the vast majority of your water will be used in the bathroom, laundry, gardening and car washing etc. |