Filters are sized according to the flow rate available and the type of irrigation used. The water used for drip irrigation will need finer filtration to water used on lawn irrigation. We stock plastic and brass filters from ½ inch to 4 inch.

Sand Filters

If the water used is either reclaimed or from a river it may require cleaning. This is usually done by a sand filter. These have been used to clean drinking water for years, but over more recent years have been used to control the spread of plant pathogens in irrigation water. As water becomes more expensive, and more restrictions are being imposed, many Sports facilities – growers – golf courses etc. are considering the collection and reuse of their irrigation water, but the potential risk of spreading disease as long been a deterrent. To help overcome this problem slow sand filtration systems have been developed and evaluated for general use, E.J. Woollard has been heavily involved in the design and construction of these systems.

The key feature is to prime the filter initially with dirty water to encourage a population of beneficial micro-organisms, which help elevate pathogens. These are active in the main body of the filter, which is a layer of suitably graded sand approx 0.5 to 1 metre deep. Dirty water passes through the sand and then through further layers of gravel; filtered water is pumped from the bottom layer of gravel into a storage tank ready for reuse as clean irrigation water. The slow sand filters must be kept running continuously, and not allowed to dry out, so when the water is not being pumped to a storage tank it must be set to recycle mode.