Irrigation Filtration
Irrigation filtration is necessary depending on the water source for the irrigation system. Some systems are sourced from the city water supply which is very clean while some systems are sourced from irrigation canals and ponds and can have different types of debris and multiple issues requiring filtration.
A new client called reporting issues with their existing filter and sprinklers clogging.
This existing filter is designed to remove sand from water and this system didn’t have any sand issues. Algae caked on the filter was difficult to remove and required maintenance more often than usual.
Filtration element materials should be specified based on what is contaminating the water and for what type of irrigation that is going to be used. Irrigation may contain sediments or algae and although both can clog irrigation components, they need to be filtered differently. Sediments can be bulky or sharp, creating the need to filter through wire screen filters while algae is slimy and can stick and bind to components which needs to be filtered through a different type of filtration element than sediments need. There is not one filter element that can handle both sediment and organic material, sometimes creating the need for multiple filters on the same system. It is important to design the appropriate filter for the target contaminant and not expect one filter to meet all of your filtration needs. Filters often get bypassed or removed because they clog too often and require too much maintenance. Most often it’s that the filter was not sized appropriately for the type of debris or the flow of water through the filter. Filters often have a maximum flow of gallons per minute (gpm) and if the flow is exceeded the filter will not perform as desired.
As algae was the primary contaminant in the water, a single disc filter was installed at first to address the clogging issues. The second season more sediment was in the water and the disc filter couldn’t filter properly with the increased sediment load.
Two filters were installed to address the two contaminants, algae and debris. The filters are installed on unions for ease of maintenance and a the client built a cover to protect the filters from the elements.
Two filters are better one, especially when they’re installed in the correct order.
The disc filter had substantially less build up after the screen filter was installed.
The type of irrigation being used also affects filtration needs as some sprinkler nozzles have a large orifice and can pass large pieces of sediment and other contaminants. Other irrigation components like drip emitters and micro-sprays can be much more sensitive to clogging and require finer filtration than most other irrigation components.
This MP Rotator clogged from running on canal water with no filtration to protect it in less than 48 hours.
Filtration needs are also important to consider for valves as well as nozzles. Debris can get caught in valves and preventing it from closing and turning off. Most valve manufactures make valves that are designed for dirty water and tolerate passing some debris. It is important to remember that a valve is not a filter though and using scrubber type valves is not a substitute for filtration.
Drip irrigation is especially sensitive to clogging and has the finest requirement for filtration in most landscape irrigation systems. Most drip valves include a pressure reducing filter as even the cleanest water systems have small debris from time to time that can clog a drip emitter. You don’t want to have to wait for a plant to die to let you know that there is a clog in your drip zone.
If you need help with your irrigation system filters, contact Water Whys Irrigation today