Do You Need a Sand Media Filter Alongside an Irrigation Water Filter?

Using two filters in an irrigation system may seem unnecessary at first.

But a sand media filter and a conventional irrigation filter are designed to deal with different types of contaminants and filtration requirements. Whether both are needed depends largely on the quality of the source water and what the irrigation system needs to protect.

It starts with the water source

Not all irrigation water arrives in the same condition. Water taken from an open well, pond, river or lake can contain silt, clay, organic material and other impurities.

For systems using this kind of source water, filtration needs a little more thought. Simply putting one filter in the line may not always be the most suitable arrangement, particularly when the water carries a considerable amount of suspended material.

This is where a sand media filter can be useful as part of the primary filtration stage.

What does a sand media filter do?

The Machclean Manual Sand Media Filter is designed for primary filtration in drip and micro-irrigation systems. It can be used to filter surface water from open sources where organic biological contaminants, silt and clay may be present.

The purpose is fairly straightforward. Water passes through the filtration media before moving further into the irrigation system, helping protect emitters from plugging.

It can also be used with fertilizers and acids, according to the specified applications.
 

Do you always need two filters?

Not necessarily. It is contingent upon the incoming water and what filtration is required. If the source water has silt, clay or organic matter that needs to be dealt with at primary filtration, a sand media filter could be an option.

In other situations, a different type of filter may be more appropriate. The available range includes screen and disc filters, as well as hydrocyclone filters designed specifically to separate sand from irrigation water.

So the question is less about whether two filters are always better and more about what each filtration stage needs to handle.

Where a second filter can help 

A primary filter deals with the initial filtration requirement, while another filter may be used to handle a different type of impurity or filtration requirement. For example, hydrocyclones are designed to separate sand from water before the irrigation process. Sand and dirt collected by the hydrocyclone can be flushed through its drain port.

Screen and disc filters, meanwhile, are available in different sizes and configurations for different filtration and flow requirements. In a larger irrigation setup, using more than one filtration stage can therefore be a practical way of dealing with different types of impurities.
 

Maintenance still matters

Adding another filter does not mean maintenance can be forgotten. The Machclean filter is designed with large service ports to make maintenance easier. Its underdrain flute design is also intended to prevent clogging and reduce pressure drop. The unit can operate in either manual or automatic mode, depending on the setup.

Other filters in the range have their own cleaning arrangements. Automatic systems, for example, can flush themselves based on pressure differential, time or manual operation. Some are designed to continue irrigation during the flushing process.

The right cleaning method will depend on the filter being used and how the system is configured.

What should you consider before choosing?

Before adding one of these filters to an irrigation setup, it helps to look at a few basic things.

Start with the water source. If it is surface water from a pond, river or lake, check what kinds of impurities are present. Then consider the type of irrigation system being protected, particularly if it includes drip or micro-irrigation emitters.

Flow requirements also matter. The filtration range includes different filter sizes and designs, so the filter needs to suit the system rather than simply being added because it is available.

A closer look at Machclean

Automat's Machclean Manual Sand Media Filter is built using reinforced glass fibre and advanced polymer technology. The construction is designed to resist impact, corrosion and chemicals, while the filter is also intended to work in high-humidity conditions.

The filter is 55% lighter than metal filters with equivalent strength and capacity. It also uses an advanced underdrain design and large service ports for maintenance.

These details matter when a filtration system needs to remain practical to install, operate and maintain over time.

So, should you use both?

There is no universal answer.

If the irrigation water contains sand, silt, clay or organic material, a combination of filtration stages may be worth considering. A sand-based filtration stage can handle the primary filtration requirement, but depending on the quality of the water and the irrigation system, an additional filter can be added for a different filtration need.

On the other hand, the right setup may involve a single suitable filtration method if that is enough for the source water and the equipment being protected.

Conclusion

The idea of adding two filters can sound like unnecessary extra equipment. But once you look at what each filtration stage is actually meant to handle, the reason for combining them becomes clearer.

The choice should start with the water source, the impurities present and the irrigation system itself. From there, filtration can be arranged around what the system actually needs.

The filtration arrangement should therefore be considered as a whole rather than choosing one filter in isolation. This makes it easier to decide whether a sand media filter, another filtration method, or a combination of both is appropriate.