Understanding Pool Cartridges Filters
Pool maintenance: Cartridge filters
Cartridge filtration is among the most recent forms of filtration. The media of filtration can either be a treated paper with pleats that are cylindrically arranged or a spun-bonded polyester. When it comes to the size of the particles to be filtered, cartridge filtration comes in the 15 to 25 micron range.
These filters come in a compact design in a huge area covering a relatively tiny footprint . They usually need almost half the filtration room area like a diatomaceous earth (DE) or a comparable sand filter. The filters are normally found in residential pools and are also extensively utilized for spa filters.
The elements from the cartridge filters are replaceable, as they go up to a period of one year. But there are a number of cleaning products in the market that are used to clean cartridge filters, thereby extending their useful life.
Substances such as oils, minerals and dirt can go through and into the elements and then back to the pool. When compared to D.E or sand filters, water velocity affects cartridge filters more.
Reason being, particles become embedded deep in the cartridge filters to the point where they are not released when cleaning the pool.
Cartridge filters are commonly used in pools and in spa water treatment to a greater extent. Basically, there are 2 concepts applicable to cartridge filtration. One – and most probably the oldest – is depth penetration filters that were designed for a 3 to 8 gpm/ft2 FMR.
Modern filters have a 0.375 to 1.0 gpm/ft2 FMR. These filters were referred to as fabric cartridges in those days. The reason being, the filters are made of a synthetic fabric in an oval or cylindrical pleated arrangement around the core.
Cartridge filtration is mostly operated in a pressure mode. However, there are a number of commercial cases where the cartridge filters are installed in a vacuum mode, which is similar to the vacuum DE system.
The reason why cartridge filtration is an obvious choice for pool owners lies in its compact design that when installing them, you will only need half the floor area of an equivalent D.E or sand system.
And since you will not need to back-wash every time when cleaning the cartridge, you will conserve a lot of water, which is an advantage when it comes to cost saving.
But, one disadvantage with cartridge filtration is that they lack a replacement or dilution component that allows one to replace dirty water with fresh water.
Water with suspended materials goes through the filters, depositing all the waste substances to the surface. And with the continual of the cycle, more debris is deposited, which constricts the passageways even more.
As smaller particles continue to be trapped, the influent pressure rises above the initial pressure level, to 10 psi.
Cartridge filters cleaning
Even though cartridge filters aren’t back-washed, they can be cleaned. All that needs to be done is to turn the pump off and then follow all the instructions given by the manufacturer.
And if there is a build-up of minerals or high water velocity, then there are further steps that needs to be taken:
To soak the element with a filter-cleaning product. And since there are instances where two or more cleaning products are needed, it’s crucial to go through label directions several times; one cleaner to remove greases and oil and the other one to remove dirt deposits.
The reason why it is important to review the label directions carefully is because the order which the cleaners are applied affects how they perform. Mostly, grease cleaners should be applied before applying the acid or any other cleaners.
Once thoroughly rinsed, any mineral deposits left are easily cleansed with a simple acid wash.
Put back the filter elements into the pool, and ensure that they are secured. Before closing the housing, ensure that you inspect the O-ring keenly.
If a wear or tear is noticed, apply a lubricant, and ensure that you do it once in every month, failure to which would lead to penetration of air to the system or even loss of water.
Some operators keep a cartridge filter as spare, such that when cleaning one filter, it can be replaced with a fresh one. And in some cases, having a spare cartridge is a requirement.