With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.
A sediment filter is used to trap and remove any suspended solids that may be present in your water supply. Sediment is composed of rust flecks, sand, grit and other debris caused by storm water runoff. This material can make your drinking water taste bad, it may look discolored or turbid, and it can cause other problems. The sediment debris can clog plumbing fixtures, damage hot water heaters, and other water using appliances. Sediment can also prevent water filtration and ultraviolet purification systems from working correctly. Installing a sediment filter is a fantastic way to protect your home from sediment damage and improve your drinking water quality. Let’s take a closer look at the available sediment filter options for your home.
A Brief Primer on Sediment Filters
Sediment is a generic term that covers all the non-liquid particulate matter found in water supplies. This includes materials, such as rust, sand, silt, soil, and clay, that are collected as the water passes through layers of rock or soil and the rusting material inside water delivery pipes. Any flow changes made by your municipal water provider can increase the level of sediment in your water, and this material can affect the performance of your water treatment systems. There are many types of sediment filters available for different applications, the filter that you need can vary depending on where you live, and your needs.
Understanding Mechanical Filtration
A sediment filter is a type of mechanical filtration, which means that the unwanted particulates are physically blocked from entering your home water supply. A sediment filter is designed to have sufficient porosity to allow the water to pass through, but the sediment can be captured down to a certain micron size. A mechanical filter uses a large surface area coupled with a sufficient gradient depth of media to filter out unwanted suspended particulates. The incoming water is actually forced through a thick barrier of filtration media that is progressively tighter as the water reaches the core of the filter.
What Can a Sediment Filter Remove?
A sediment filter is rated to micron capacity; it can remove visible particulate matter and cloudiness caused by a high concentration of suspended solids. These types of filters cannot remove other contaminants, such as bacteria, pathogens, chemicals, or heavy metals. A sediment filter cannot improve the taste or smell of the water, and they are best regarded as a passive defense measure to protect sensitive water filtration components. This is why sediment filters make a great addition to a reverse osmosis (RO) and/or ultraviolet (UV) water purification system(s).
Four Water Treatment Systems Protected
Let’s take a closer look at four key water treatment or purification systems that need a sediment filter to protect critical components and maintain efficiency.
- Reverse Osmosis (RO)
Every RO filter system needs a sediment pre-filter to remove potentially damaging particulates. An RO filter forces the water through a semi-permeable membrane under pressure to remove salts, metals, and total dissolved solids (TDS). This purifies the water for further filtration, disinfection, and conditioning systems to provide an unparalleled level of quality. But, the water that’s rejected by the membrane has to drain away via small flow restrictor, and this is vulnerable to sediment damage. If the flow restrictor is clogged with particulates, the RO membrane cannot be pressurized, and this will affect the recovery ratio.
- Ultraviolet (UV) Purification
A UV purification system uses ultraviolet light at certain wavelengths that are known to have germicidal properties. The UV light works by damaging the DNA of any microorganisms present. This prevents them from replicating, rendering them harmless for human consumption. This system is extremely effective, but it doesn’t work well if there is a lot of turbidity or cloudiness in the water supply. The presence of suspended particulates prevents the penetration of ultraviolet light into the water, and this significantly diminishes the efficacy. So, bacteria, viruses, and other pathogens can pass through and contaminate the water supply. If you have a UV purification system, it’s essential to install a sediment pre-filter of at least 5 microns in size.
- Carbon Filtration
Many people use carbon filtration systems to improve the taste and smell of their drinking water. Carbon is very effective at removing the chlorine and chloramines that degrade the aesthetic qualities of water. A carbon filter can also filter sediment, but the particulates will clog these filters up quickly, and the filter media is exhausted. If a carbon filter is used for sediment filtration, the useful lifespan of that filter is significantly reduced, and it will need to be replaced more frequently. It’s far cheaper to replace a sediment pre-filter than a more expensive carbon filter block. So, if you want to save money and avoid replacing filters more often, it makes sense to install a sediment pre-filter.
- Whole House Sediment Filters
This type of system will remove all of the sediment coming into your home. This is a fantastic way to protect all of your plumbing systems and water using appliances from damage. Over time, sediment will build up, and this will clog plumbing pipes leading to narrower internal pipe diameters and a lowered water pressure. Appliances will have deposits of accumulated sediment present inside, and this will reduce efficiency, make repairs more likely and lower the lifespan of the equipment. This is equally applicable to public and well water supplies, and well water often contains more sediment.
Sediment Filter Types and Sizes
There are several different types and configurations of sediment filter cartridges available, including pleated, melt-blown, string wound, bag, and spin down filters. Despite being different, they all serve the same basic function; they capture sediment and prevent it from entering your home. The filter capacity will be rated in microns, each micron is one millionth of a metre, and the rating indicates the particle sizes that the filter can remove. As an example: a 5 micron sediment filter will remove and particulates large than 5 microns in size. To put this in perspective, anything less than 35 microns in size can only be viewed under a microscope, and a human hair is around 75 microns wide. The size of the sediment filter you need will vary on the sediment that you need to remove, but an RO system will work well with a 5 micron filter system.
If you want to learn more about sediment pre-filters, RO filtration, and UV purification systems, contact your local water professional.