Maintaining your rainwater harvesting system
Posted by Barry Nutley on 22 July 2009 at 9:10 am
How much maintenance of a rainwater harvesting system is needed, is a common question. As with any appliance, regular maintenance ensures optimum performance, and increases life. So here I aim to answer some of the common questions:
1. Do I have to clear the leaves out of the filter?
Not necessarily. This depends upon the system you choose. Some products have "basket" type filters in the downpipe or turret itself. You will need to check this regularly and clear any leaves if necessary. How often depends on the time of year and proximity to trees etc. Naturally you will tend to need more checks in autumn, when leaf fall is greatest, than in spring. Over a period of time, you will be able to work out your own maintenance schedule.
However, some products have a filter with a nearly-horizontal mesh filter from which leaves are washed away by the arriving rainwater. This makes them pretty much maintenance-free as far as leaves are concerned. Typically, this type of system costs a little bit more.
2. Does leaf debris or sediment get into the stored water?
Yes. Most tanks accumulate a millimetre or two a year, but there are devices which reduce this:
a) A calmed inlet prevents arriving water from disturbing any silt in the system.
b) A siphon on the overflow sucks dirt off the surface of the water
c) A floating intake takes rainwater for the house from just below the surface of the water, where it's clean.
Again, there is typically an added cost involved.
3. How often should I clean the sediment out?
The tank manufacturers mostly say you should inspect the tank for silt build-up every couple of years, but it can be much longer before any intervention is required. To get the silt out, lower a dirty water pump to the bottom of the tank when it's nearly empty and pump out the silt with the remaining water. A hose or pressure washer could also be useful.
4). Does the pump need maintenance?
The pumps tend to be strong and long-lasting. They shouldn't need any maintenance. If you have a submersible pump, then there are no user-serviceable parts. In the case of breakdown the pump can be pulled out with its cord (the top of which is usually attached to the inside of the tank turret at installation) and replaced. Typical cost of a replacement pump is around £200. But do check on the warranty. The tanks will have a long warranty, but 2 years warranty is usual for the pump.
Photo by lepiaf.geo
If you have a question about anything in the above blog, please ask it in the comments section below.
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