Backwash or backwashing is the process of thoroughly cleaning a swimming pool 's filter by a method of reversing the flow of water to flush out contaminants. This way, you don't have to clean the filter manually, and it usually takes just a few minutes.
Continue the process until the water runs clear through the waste line. You'll know that it's time to perform the backwashing routine when the pressure gauge indicates a pressure rise of pounds above the clean or "startup" pressure. Maintenance and prevention are key: When you feel a backwash valve becoming difficult to turn, do a teardown and lubricate before any leaks occur.
While you're at it, carefully examine grids, laterals, cartridges, and manifolds each time you break down a filter for cleaning. While each type of filter will keep your pool clean, the key to keeping it that way is by making sure the filter is the correct size and is regularly cleaned. So, what's the best type of filter? The one you're most likely to keep clean. Cartridge filters are often a popular choice because they are easy to maintain.
Choose the filter that fits the size of your pool. Backwashing a DE filter should be considered a temporary solution when a complete teardown and cleaning aren't practical. Since there is no DE to add, it removes the potential for errors that may result in a dirty pool.
Backwashing Water Filters Basics
Instructions vary according to your filter type; it's best to consult the website of the filter manufacturer, if possible.
Basically, this is how it is done with a DE filter:. Backwashing and teardown depend on how often you use your swimming pool and just how dirty it actually gets with normal use. DE filters are usually torn down and cleaned at least six times per year. Unless your pool gets really dirty, you should not need to backwash it beyond your scheduled maintenance. Sand filters, however, can be backwashed once a month and are typically torn down two times per year. To backwash a sand filter:.
You can save energy by running the pump at a lower speed after cleaning the filter. This can be achieved without reaching a point of no-flow or low-flow. If dirt or DE diatomaceous earth gets through the filter and into the pool, check for:. Damaged grids, laterals or cartridges Broken manifolds or retainers Backwash valves that have bad gaskets or O-rings.
Turn off the pump and turn the backwash valve plunger or multivalve to the backwash setting. Turn on the pump again until the filter view-glass appears clear. Try to alternate between backwash and rinse or filter for plungers a few times to remove more DE. Don't forget to turn off the pump when changing valve settings. Discard the DE in the yard or in the trash. Some units include a DE separation tank that captures and contains the DE. Turn off the pump to make sure that the timer or automation system doesn't turn back on while the filter is being disassembled.
Drain the filter by opening the release valve at the top of the filter to allow the water to drain. For thorough draining, remove the drain plug sometimes by using a screwdriver at the bottom of the filter so the water can drain from the tank's bottom. Lock it in place While turning on the system, open the air relief valve, which is located at the top of the filter. Leave it open until water flows through Close the valve and shut off the system. Read More.A backwashing filter is a water filter that cleans itself periodically by rinsing away impurities it has filtered from water.
Although a backwashing filter may look like a water softener and be the same size, it's a different animal. Softeners are "ion exchangers", not filters. A backwashing filter is a simple device that consists of a large tank called a "mineral tank" that is filled with a filtering substance called a filter medium. The plural is media.
Water enters the top of the tank through a special control valve and passes downward through the medium, which removes impurities and holds them. Some media do not hold impurities, but cause a change to occur. Calcite, for example, dissolves and in the process increases the pH of acidic water. The treated water then enters a tube at the bottom of the mineral tank, passes upward through the tube called a riserand exits the filter via the control valve.
When the filter medium is saturated with contaminants, the control valve initiates a backwash.What’s The Best Iron Filter
The backwash is an operation in which water passes backward through the filter at a rapid rate. It enters the tank at the bottom via the riser tube, then passes upward through the filter medium, exiting at the top, via the control valve.
The rapid upward flow, in addition to washing away stored impurities, fluffs and resettles the medium bed, preparing it for another filtering cycle. Filter media are selected according to purpose. Some of the most common are Birm iron removalFilter Ag sediment removalCalcite increase pH of acidic waterKDF55 chlorine and lead removalKDF85 iron and hydrogen sulfide reductionManganese Greensand iron and sulfide removaletc.
Some media have numerous applications, like the very useful and widely used GAC, or Granular Activated Carbon, which is used to remove chlorine, the by-products of chlorination, pesticides, herbicides, and chemicals in general. GAC, following proper pretreatment, also removes iron and hydrogen sulfide.
It comes in various formulations made from a variety of materials bituminous coal, coconut shells, wood, etc. This site includes a useful Filter Media Guide and a second guide that gives flow and backwash features of the various media. Choosing a backwashing filter can be a simple or a complex issue. You should not expect a backwashing filter to be a magic, one-step solution to any problem. Often, in fact, it is the final stage of a more complex treatment system.
By Mark Timmons. The Truth About Air Injection Iron Filters It seems that these days everyone in the water treatment business is selling an air-injection iron filter. They market these as "chemical-free iron filters" and some do work Then they may fail sooner. If you have "low to moderate" iron, they may work for a while, but many are doomed to failure in the long-term.
That's how it works and it really sounds great, doesn't it? The iron is not fully oxidized and it forms a tremendous amount of "iron sludge. Then, the iron that has accumulated in the media and internal parts and plugged the injector continues to build up.
The system is overwhelmed with iron sludge and ceases to work. Within a few months, the eductor injector is plugged with iron sludge and the water softener control value quits drawing air. It does nothing. The iron continues to build up and soon thereafter, the system is overwhelmed. Sometimes it simply shuts down from sludge and the flow is greatly impacted.
Most of the time, you just start noticing iron stains and by the time you do something about it, it's too late. There's one way to make sure your air injection system doesn't stop working and that is to disassemble the valve every months, clean the parts with chlorine or sodium hydrosulfite and sodium metabisulfite, being sure to clean the injector assembly so as to allow it to function properly.
It's probably a good idea to clean out the media with chlorine or sodium hydrosulfite and sodium metabisulfite as well. Now, if that seems like a lot of work, it is.
How Backwashing Filters Work
So, some customers just add on a room and let their local water treatment company technician live there OK, that's just sarcasm, but you get my drift. So, what is the solution? It's simple for us - we use H2O2 instead of Oxygen - It's a much better oxidizer than oxygen and it doesn't require that a service technician move in with you.
Hydrogen Peroxide works every time and since it is such a great oxidizer, it does not leave all that iron sludge to clean up and there are no injectors to plug. We sell systems all over the world. We sell direct and eliminate-the-middlemen, so we can't send out a service tech every time you have a problem. I know that people are going to write in and say that they have an air-injection iron removal system and it works, but they don't work enough of the time that we can promise it will remove the iron or sulfur.
We can make that promise with hydrogen peroxide. No kidding around. Find the update HERE. December 27, Mark- Nice analysis on a common problem. I appreciate your humor, too. But I am looking for a rust removal system for a well-sourced water supply Florida coast lawn irrigation application. Note: Well is not used for household use.Name brand equipment, including high quality Terminox iron filters. Great warranties, and budget prices!
Some of the highest quality iron filters use a media called Terminox. Terminox, a naturally mined ore, is a mineral form of manganese dioxide which has been used in water treatment for more than 75 years.
Terminox is a granular filtration media for hydrogen sulfide, iron and manganese reduction. Terminox functions as a catalyst, but itself remains relatively unchanged. Terminox works on a principle whereby the hydrogen sulfide, iron and manganese are oxidized and trapped on the media while simple backwashing cleans the bed.
No chemical regeneration is required, nothing is imparted into the drinking water and Terminox has a high capacity for low contaminant concentrations. Terminox can be used in conjunction with aeration, chlorination, ozone or other pretreatment methods for difficult applications.
Chlorine or other oxidants accelerate the catalytic reaction. A filter has three different operations that it performs. The head controls these functions and they are as follows: Service - During service filtration the water is directed down through the filter media where the particles in the water are trapped. Once the water has reached the bottom of the tank, it returns to the top of the tank through the distributor.
Backwash - The head will determine when the system needs to be backwashed or regenerated based on elapsed time or water usage. During backwash the head will direct water down through the distributor and up through the media. This flow will be of enough force to actually lift the media and shake lose any trapped particles.
The water that leaves the top of the tank is directed to the drain. Rinse - Once the media has been backwashed, it is rinsed by again sending water down through the media and then to drain. This will rinse any lose material at the bottom of the bed and in the riser to drain. Once rinsed, the filter will return to service. If you are interested in high quality Terminox iron filters.
Budget Water Info. Mesh Size: 8 x 20 Effective Size: 0.Aeration Systems for Water Treatment. Undersink Filters. Backwashing water filters are large tank-style filters that get their name from the fact that they clean and renew themselves by backwashing. Backwashing consists of reversing the flow of water so that it enters from the bottom of the filter bed, lifts and rinses the bed, then exits through the top of the filter tank.
The filter bed itself is a granular substance that is usually referred to as the filter medium. Media media is plural, medium is singular are numerous and varied. Common media are granular carbon, sand, garnet, anthracite, zeolite, granular manganese dioxide, and greensand.
The picture above shows the filter in "service" position. This is how it works when it is doing the job it is designed to do. The unfiltered water enters from the left and is routed by the control valve into the filter tank. The water then filters slowly through the medium until it reaches the bottom of the tank where it is collected through a specially-designed sieved "basket" at the bottom of the center tube seen in the picture. The filtered water then passes up through the center tube, called a "riser" or a "dip tube," passes through the control valve, and exits the right side of the filter.
Note that there's a drain line in the picture, but no water goes through it during the filter's "service" function. As the filter operates in the service mode, it traps and holds particles in the filter bed. Also, since water's nature is to follow the path of least resistance, after a time it begins to cut channels through the medium. As channels or holes in the media bed form, water begins to flow around rather than through the medium.
This process is called "channeling," and it can reduce the effectiveness of the filter considerably.
Pure Water Gazette How It Works Series
At a preset time, the control valve initiates a "backwash" to clean the medium of collected particles and to resettle the bed and eliminate channels that have formed. The backwash is accomplished by sending water down the riser tube from which it enters the filter tank at the bottom. The force of the water is such that it actually lifts the media bed, swirling and tossing the granular medium.
The water leaves the filter tank through the control valve, which routes it through the filter's drain line. Particles that were being held in the bed are washed to drain. The backwash is an intense rinsing and tossing of the medium that lasts for several minutes. In a standard residential filter, a typical backwash lasts about ten minutes. After the backwash, the control valve initiates a "rinse" of the bed during which water flows downward through the medium, up through the riser tube, and out the drain.
The purpose of this rinse is to rinse and settle the bed and prepare it for return to service flow. Mineral tanks are very strong and usually guaranteed for up to ten years by the manufacturer. Control Valves. Most modern filters use timer-style controls in which an electric timer initiates and controls the backwash of the filter at a pre selected time. Meters, which backwash the media when a certain number of gallons have been treated, are used widely on water softeners but much less frequently on filters.
Some very sophisticated setups can initiate backwash in response to a pressure differential between the incoming and outgoing water, but for most situations, the standard, reliable timer control is preferred on backwashing filters. With a few minor modifications, a backwashing filter can serve many different purposes according to the filter medium used.
Here are some of the more common granular media used in backwashing filters:. Granular Activated Carbon. Carbon can also remove sediment and even iron if the iron is pretreated properly.
It is the most commonly used medium for hydrogen sulfide reduction. Granular carbon is the preferred treatment for many chemical contaminants.In terms of water treatmentincluding water purification and sewage treatmentbackwashing refers to pumping water backwards through the filters media, sometimes including intermittent use of compressed air during the process. Backwashing is a form of preventive maintenance so that the filter media can be reused.
In water treatment plants, backwashing can be an automated process that is run by local programmable logic controllers PLCs. The backwash cycle is triggered after a set time interval, when the filter effluent turbidity is greater than a treatment guideline or when the differential pressure head loss across the filter exceeds a set value.
Water treatment filters that can be backwashed include rapid sand filterswater softening systemspressure filters and granular activated carbon GAC filters. Diatomaceous earth filters are backwashed according to the proprietary arrangement of pumps, valves and filters associated with the filtration system.
To keep water treatment filters functional, they have to be cleaned periodically to remove particulates. Ineffective backwashing is one of the main reasons that water treatment filters fail. Backwashing of granular media filters involves several steps.
First, the filter is taken off line and the water is drained to a level that is above the surface of the filter bed. Next, compressed air is pushed up through the filter material causing the filter bed to expand breaking up the compacted filter bed and forcing the accumulated particles into suspension.
After the air scour cycle, clean backwash water is forced upwards through the filter bed continuing the filter bed expansion and carrying the particles in suspension into backwash troughs suspended above the filter surface. In some applications, air and water streams are simultaneously pushed upwards through the granular media followed by a rinse water wash. At the end of the backwash cycle, the upward flow of water is terminated and the filter bed settles by gravity into its initial configuration.
Water to be filtered is then applied to the filter surface until the filter clogs and the backwash cycle needs to be repeated. Some water treatment filters use surface wash systems that break up the heavily clogged, granular media surface layer. Surface wash systems are buried in the top of the filter media or are suspended above the filter media surface.
John R. Baylis developed a fixed grid system which consisted of pipes with nozzles that injected jets of water into the filter material during expansion. A surface wash step in a backwash cycle usually takes place at the beginning of the filter bed cleaning process. Spent backwash water is either discharged without treatment to a sanitary sewer system or is treated and recycled within the plant. Used backwash water contains high concentrations of particulate material.
Typical treatment processes include coagulationflocculation and sedimentation. Failure of a backwash treatment process and reintroduction of the resulting poor quality water into the main water purification plant flow stream can cause overall process upsets and result in the production of poor quality treated drinking water. As a water conservation measure, many water purification plants recycle filter backwash water and other product streams from sludge treatment processes back to the beginning of the plant.And no harsh chemicals, salt or maintenance.
Just "set it and forget it". Compare to other filters costing three times as much! It has a much better filtration capability than Birm Filters or Air Injection and Pump methods when you have iron in your well water. Iron removal removes Sulfur and Manganese as well using potassium permanganate regeneration. Beautiful filter unit with white insulating jacket. Large 10"x54" mineral tank for even the toughest jobs.
Polyethylene lined fiberglass wound mineral tank other sizes available upon request. Latest high tech digital performance valve. InLine Filters. These in line filter cartridges for iron removal in small amounts. They remove red water iron, not clear water iron.
So if your iron in the water is rusty water you can see, then these may offer some relief. Rusty water is usually red or orange in color. If the water is brown with no hint of red or orange to it then it is likely not rust. It is probably sediment.
A simple water test for iron will let you know for sure whether you have iron. Keep in mind you can send us a sample and we will test it for free. A Pyrolox iron filter is best if there is a lot of iron in water wells. Please Note: Remove iron from water as well as Sulfur, Manganese, Turbidity, Chlorine, Dirt and many other contaminants from the entire home or house.
These Whole House Iron Filtration Systems are of the highest quality and designed to last many years. When removing iron from water be sure to ask for advice from our technicians. Iron and water don't mix.