Does a cartridge filter need to be backwashed also?
No. Cartridges are cleaned by removal and spraying with a hose. It is usually best to let the cartridge dry after cleaning before replacing it back in the filter.
How can I tell when a cartridge filter element needs to be replaced?
With no moving parts or electrical switches to fail, cartridge elements do not have a defined termination point. Instead the fine interstices of the media matrix gradually plug up over time. In a typical spa, the culprit that plugs the media is perspiration and body oils combined with soaps, chemicals and very fine particulate. In a swimming pool, the loading is primarily debris along with sun tan lotions and organic matter such as algae.
Assuming the filter is properly maintained and correctly sized to the pump, determining when the cartridge is exhausted depends primarily on three factors: 1) Shorter cycle time between cleanings; 2) Low water flow rate and high differential pressure; and 3) Catastrophic failure such as a tear in the media or center core collapse. All three are dependent upon proper pool or spa water chemistry and following a routine maintenance schedule. Homeowners should be reminded that filter elements are plastic and should be handled and maintained accordingly.
How can you tell if your system is plumbed backwards?
Peel back the broken top and examine the pleats. Is there dirt accumulation on the inside of the pleat pack?
Does the support band on the outside of the cartridge, if present, appear stretched and wrinkled?
Do the outside of the pleats appear rounded and puffy?
If you are still not sure if your filter is plumbed backwards, shut down the entire system and completely bleed the canister pressure. Remove the cartridge and with the lid off quickly turn the pump on and off. Observe which port is delivering the feed water and assure that it is the "inlet." (Always consult the manufacturer's instructions before removing the canister lid or working on any pressurized system.)
How do I know when it's time to clean my pool filter?
Normal, periodic rinsing or backwashing will remove most of the dirt from a basically clean filter. However, over a period of time, grease, oils and scale can attack and build up on the elements. When this occurs, you will see build up on the removable elements, short filter runs, reduced circulation and water that does not want to clear up.
How often does a cartridge filter need to be cleaned?
The frequency of cartridge maintenance will depend on many factors including the size of your filter, flow rate of your plumbing, and bather load in your pool. You will know when you need to clean the cartridge by the pressure reading on your pool filter. A good rule of thumb is to remove and clean the cartridge when this reading is above 15 pounds.
How often is it necessary to backwash my pool filter?
The frequency of backwashing will depend on many factors including the size of your filter, flow rate of your plumbing, and bather load in your pool. You will know your filter needs to be backwashed when the pressure reading on your filter reaches the specified level (as set out in the filters manuals guidelines). Whenever the pressure reaches this level the filter should be backwashed. It is ususally 10-15 psi higher than the psi when the filter was new of just thoroughly cleaned.
How often should I backwash my filter?
The filter should be backwashed at least weekly and whenever the filter gauge reads 10 lbs. higher than what it does after backwashing and rinsing the filter.
Is there an easy way to know when to clean a cartridge filter?
Yes! Cartridge filters work on the "clarification process." They utilize the debris they collect as an aid to improve filtration. As a result, cleaning too often does not allow the filter to work at optimum filtration efficiency, while not cleaning often enough will shorten the life of a cartridge element.
So here's a tip. When you replace the element with a new one, note the start-up pressure on the tank gauge. This reading is the system's total pressure in "pounds per square inch" or psig (gauge). Mark this point with a drop of fingernail polish or a grease pen. Then add 8 pounds to the reading and place another dot. You now have the normal operating pressure for your cartridge in psid (differential). Allow the filter to operate between these two points and clean whenever the gauge reaches the higher pressure mark.
Sharp pleat folds vs. rounded pleats -- is there a difference?
Absolutely! One of the first things a filter expert will look for when examining a pool or spa element is the pleat fold or "knuckle radius" of the pleat. Why is this important? If you look carefully, you will notice that some manufacturers' pleats are very sharp while others are rounded and even appear puffy. With Reemay or other spunbonded polyester medias it is much easier to make a rounded fold than a sharp pleat. Moreover, a rounded fold can mask the filter manufacturer's inability to make straight pleats or maintain proper pleat spacing.
Some cartridge end caps are hard and others are soft. Some cartridges have one hard end cap and one soft end cap. Why is this?
When cartridge manufacturers design a new filter element, several factors must be considered. One of the most critical is end cap hardness. To determine the exact degree of shore hardness required, we first must look at the element sealing points. Sealing points both position the element and prevent water by-pass.
Historically, single cartridge systems all used cartridges with inside i.d. friction seals with hard end caps. This design provided both strength and pleat support. However, as filters became more sophisticated, so did end cap design.
Sta-Rite's Posi-Flow element, for example, uses a soft vinyl bottom to both seal the inside and outside edges and lock the cartridge into the filter base, while the top end cap is a hard compound for cartridge strength and integrity. Hayward's Star Clear filter uses hard end caps for integrity with a soft gasket to allow a knife edge top seal. Both the new American Predator and Jacuzzi CFR designs rely on a soft top and bottom to achieve an o-ring seal. These end cap configurations are excellent designs. Only the compounds change to meet the manufacturers' specifications.
This is another reason why Unicel builds its replacement cartridges to OEM design specifications, and why Unicel is number one in quality and reliability.
What does the term "plumbed backwards" mean?
Simply put, waterlines that attach to the "inlet" and "outlet" on the filter canister were reversed during installation. In this case, the water flow through the filter element will be from the "inside-out" rather than the "outside-in" (as the filter was intended). Debris rapidly accumulates on the inside of the pleats, water flow is restricted, and the cartridge begins to expand. Eventually, the cartridge's end cap will split, releasing the internal pressure. The filter element is now being by-passed in the filtration cycle.
What is a cartridge filter?
A filter that utilizes a pleated, porous medium as a filtering material.
What is the "residential" flow rate for swimming pool cartridge filters?
Filter manufacturers size all three systems in accordance with the National Sanitation Foundation (NSF) Standard 50 "Circulation System Components for Swimming Pools." Those ratings are as follows:
*High-rate sand - Max flow rate 25 GPM per square foot of surface area, normally sized between 15 and 20 GPM per sq. ft. A minimum flow rate of 11 GPM per sq. ft. is required to utilize the torturous path filtration of depth type filter media. Flow rates over 25 GPM can lead to channeling.
*Diatomaceous Earth (DE) - Max flow rate 2.5 GPM per square foot of surface area, normally sized at 2 GPM per sq. ft. Proper flow rate and pressure are essential to assure a uniform cake formation on the support grids.
*Cartridge - Max flow rate 1 GPM per square foot of area, can be sized between 0.25 GPM and 1 GPM per sq. ft.
What type of swimming pool filter should I use in my swimming pool?
The three main types of pool filters you have to choose from are: cartridge filters, sand filters, and diatomaceous earth (D.E.) filters. Each filter has different strengths. Your decision will be based on what is more important to you: the cleanest clearest water possible, or ease of maintenance.
Which pool filter involves the least amount of maintenance?
Cartridge pool filters have won over many pool owners for their ease of maintenance, simply open the housing, pull out the filter cartridge and wash off. Cartridges can also be soaked in special solutions to remove mineral deposits. Sand filters are also very easy as far as maintenance. The sand filter is designed to allow for backwashing that will knock loose accumulated debris leaving the sand clean and ready for more filtering of your pool water. Of the 3 types of pool filters the diatomaceous earth (D.E.) filters require the most detailed maintenance routine.
Which type of swimming pool filter will keep my pool the cleanest?
The smaller the particles the pool filter will trap the cleaner your pool will be. Diatomaceous earth (DE) pool filters are widely recognized for filtering down the smallest particles of any pool filters (3-5 microns). Any particle under 40 microns is invisible to the human eye but large quantities of these size particles can cause water to appear cloudy. After a diatomaceous earth (D.E.) pool filter, in order of pure filtering capabilities, come cartridge filters and then sand filters respectively.
Why is filtration important to the quality of swimming pool water?
Filtration is the mechanical system for removing visible matter from the water. The filter medium is designed to remove hair, dirt, minute skin flakes, metal or calcium precipitates and other visible debris that would otherwise cause the water to be hazy and cloudy.
Why is there such a wide variation in flow for cartridge filters?
Unlike DE or sand filters where the flow rate needs to be specific to optimize the performance of the filter system, cartridge filters can work at any flow rate. In fact, the lower the flow per square foot, the more efficient the system works.
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