What size water filter should I have if I’m irrigating rainwater?

 Min read
May 18, 2023

Chris has been thinking about using rainwater for irrigation purposes. He knows if he’s going to do this that he wants to implement some sort of filtration system. Unfortunately, he doesn’t know where to begin. The good news is that Vu-Flow has a couple of options available that are good for filtering rainwater.

Some people may not realize it, but rain is actually a good alternative option to make use of when it comes to certain applications that utilize water. It’s a great use of something natural that can help to conserve other resources that you may otherwise use. Rainwater can be used for watering plants, cleaning, bathing, or drinking.

The CDC points out that rainwater may not be as pure or clean as you would think. Water that may have been collected by someone may be contaminated by a variety of different contaminants washed off by rain. Bird droppings, for  example, can be pulled off a roof and end up in either a barrel or tank that’s being used for collection. Ultimately, rainwater can carry bacteria, parasites, viruses and chemicals. All these things can be harmful to  human health, but they can also be damaging to plant life, so this is something to think about if you’re using rainwater for irrigation purposes.

More so than the problems listed above, the biggest concern when it comes to irrigation is making sure your system stays free of any debris that could cause unnecessary and sooner-than-normal wear and tear. Objects including large sediment, dirt or small rocks are all things that can get into your irrigation system if you’re utilizing rainwater and cause some serious damage. This of course can lead to needing to spend money on costly repairs.

There are several parts of an irrigation system to be concerned about if you’re allowing untreated rainwater to run through it. Clogged emitters or sprinkler heads are probably the number one worry to have if the water running through your system contains larger debris.  In addition to the risk of causing long-term damage to the parts, if left uncleaned, blocked emitters can impede the proper distribution of water, resulting in unhealthy plant growth.

Allowing large debris to run through your system can lead to damaged pipes as well. It may take longer for this to become noticeable, but rest assured that dirt or rocks scraping against the inside of pipes over time will lead to them needing to be replaced  sooner or later. This can also lead to parts of the actual pipes breaking loose. If this happens, and the pieces travel down your system’s line, emitters, and sprinkler heads can end up getting clogged from this as well.

If you are currently using rainwater for irrigation or thinking about doing so, it should hopefully be obvious by now that you’ll want to implement some sort of filtration system to clean everything up. Vu-Flow has a couple of different options to consider for doing this.

A Screen Filter or Sand Separator from Vu-Flow can help you to get the job done. The first thing you’ll want to know if you’re going to select one of these filters is exactly how much flow you have running through your system. There are four different filters to choose from when it comes to inlet and outlet sizes, and the one you choose should be based on the amount of flow moving through your system. A ¾" or 1” filter is designed for systems that have anywhere between 1-25 gallons per minute (GPM) of flow. A 1-½" filter is good for a system that has 10-50 GPM and a 2” filter should be implemented into a system that has 18-100 GPM.

After deciding which one of those options is most appropriate for your system, you’ll also want to figure out which mesh size to go with. Vu-Flow offers a variety of mesh sizes with 24 mesh being on the coarsest end of things and 1000 mesh being on the finest end. For any water you use for irrigation purposes, including rainwater, most of what you’re concerned about filtering out will be of the larger variety. This means you’ll likely want to select a mesh on the coarser side of the spectrum, otherwise, you’ll need to flush your filter out constantly. With this in mind, we would recommend picking either 24, 30, or 40 mesh to put into your filter housing.

More recently, Vu-Flow launched a new filter option you may want to consider using if you’re trying to clean up rainwater for irrigation in the form of a Y-strainer. Y-strainers are good to use in applications that utilize low flow, so if your scenario includes a drip irrigation system, this may be the filter for you. These filters are offered in either ¾", 1”, or 1-½" sizes and have a compact build making them easy to install in small spaces. Y-strainers are chemical resistant and can be purchased with either a mesh or disc insert for filtration. The filter housing design has a large capacity, so you won’t need to flush or clean them out as often. Similar to the Screen and Sand Separator filters sold by Vu-Flow, Y-strainers are easy to install and maintain.

If you’re planning on using rainwater for irrigation purposes, be sure to give Vu-Flow a call to get more details regarding the different filtration options available to you. Dial 1-800-833-5171 where a live customer service representative will be glad to help you out.

Source Notes: Information in this article relating to the harmful debris in rainwater came from the CDC.