Reed Filtration Beds

Another project we have been asked to help with a lot in recent years is plants and advice for creating reed filtration beds. With the population becoming more mindful of their impact on the planet, reed filtration systems are another way for us to work with nature to improve water quality. Passing water slowly through the roots of reeds, grasses and rushes helps to restrict the movement of pollutants and the plants help filter the water by removing other impurities.

Building a filtration reed bed

There are two basic ideas for building a reed bed system, a vertical filtration system or a horizontal system. This refers to the way in which the water flows through the system. In either case we would advise lining the reed bed with a plastic or preformed liner. If space is tight or you need to deal with stronger effluent a vertical system would be best. Vertical reed beds work by passing the wastewater over the top of layers of sand and gravel planted with reeds. The water slowly passes down through the layers and between the roots where it is filtered and collected in outlet pipework. A horizontal bed is the same principle but built on a gentle slope and the wastewater is introduced at the to end and the effluent passes through the gravel and roots slowly down the slope and on into an outlet pipe. You can pass the wastewater through multiple beds for increased filtration.

Plants for reed beds

By far the most popular and efficient plant to use for a reed bed system is common reed (Phragmites australis) but Bulrush (Typha latifolia) is a decent alternative. If the bed is of good size and its efficiency isn’t the most important thing Rushes and yellow flag iris can be added for more interest. When first planting reeds into the system we recommend a minimum of 5 plants per square metre, this is best done with 230cc root trainers. You can do this with smaller plug plants, but it would be a good idea to increase the minimum quantity to 9 and these plug plants may require watering until their roots grow further down into the gravel. These are minimum numbers, for a quicker establishment of the reed bed you can plant more per square metre, 9 x 230cc root trainers would be more effective. Please feel free to check out our website for all our current stock of reeds, rushes and other pond plants