Expert advice on installing a grey-water system in your home

06 November 2016 - 02:00 By Roberta Thatcher

We chat to William Heslop of Baobab Water Solutions about installing a grey-water system - and get some tips about the best way to use it Is it complicated to install a grey-water system?As long as the plumbing is suitable, it is not difficult at all. The drain pipes from the bathroom must be visible and accessible and not flow directly into the sewerage system underground. You should also plan for a gully for overflow water. Some pipes come out very close to the ground or are directed below paving into the gully, which makes them difficult or impossible to reach. Electricity will also need to be accessible.story_article_left1How does a grey-water system work?There are several systems available on the market and they generally all work on the same principle. The water is fed into the system where is passes through a filter and is then pumped out into the garden. Grey water should not be stored, as it becomes smelly and unhygienic.How big is a system?The size can vary, but it is usually around 60 to 70cm long, 40 to 50cm wide, and 30 to 40cm high. The water needs to reach the garden either through an underground drip line or normal garden hosepipe.How much household water can be recycled?Shower, bath and basin water can be collected from more than one bathroom if the drain pipes are not too far apart. Water can also be collected from the washing machine, unless it is used to wash nappies or clothing soiled by faeces and/or urine. Water from dishwashers and the kitchen sink is not suitable as it is greasy and contains food particles, making it unhygienic.Can you expand on a system or should you go large from the beginning? As grey water is not stored but pumped straight into the garden, the size of the system is not a factor. Further systems can be added later, as long as the accessibility of drainpipes, space for the system and so on is taken into account at the time of building.story_article_right2What can and can't you use grey water for? Research by Rand Water and Unisa has shown that the quality of filtered grey water is safe to use for irrigation in the garden. It can be used for vegetables, but plants should be flushed occasionally with fresh (rain or tap) water and grey-water irrigation should be stopped a couple of weeks before harvesting. Fruit and vegetables should not be irrigated from above if they are to be eaten raw. Grey water tends to be alkaline, which is generally beneficial to plants. Acid-loving plants, such as azaleas, begonias, ferns, proteas and fynbos, should not be watered with grey water. It is usually recommended that in the absence of rain, tap water be occasionally used to flush your plants.Grey water should not be used in swimming pools or garden ponds as it may contain pathogens. Grey water cannot be used with a mist spray or regular drip line as particles will block the fine holes in these systems. There are drip-line systems that have been designed for grey-water usage.Must you use organic beauty and laundry products if you have a grey-water system? Some ingredients in detergents and soaps can be harmful to plants, but some are beneficial. Biodegradable products improve the quality of the grey water, particularly laundry products. The biggest problem with laundry water is fabric softeners, as these clog the filters. ..

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