Backwashing is a pool term used to describe a filter cleaning method which reverses the flow of water through your filter system.
As a general rule, you should be backwashing your pool about once a week or in conjugation with your scheduled maintenance. Another industry standard is to backwash when your filter's pressure gauge reads 8-10 PSI (pounds per square inch) over the starting level or “clean” pressure.
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.
Any backwash water is to bypass the septic tank and be discharged to the drain between the septic tank and the common effluent drain. Under no circumstances should backwash water be discharged into the septic tank.
It is not recommended to drain a swimming pool through the backwash valve. While sucking from the main drain and putting the water down the backwash line will work in some scenarios it puts your pool pump at risk of losing prime and running dry.
Backwash runs it through the sand in the opposite direction. Rinse is to clear any dirt out of the clean side of the sand before you start sending it back to the pool.
You can do your part to protect the environment
Use the backwash to water grass or any area on your property that will allow water to percolate into the ground. Backwash pools directly into the private sewer cleanout on your property instead of into the storm gutter.
Whenever the filter fills up with the dirt/debris it reduces the flow of water to your pool. Low flow = poor circulation which will lead to algae in the pool. Bottom line, the filter must be backwashed on a regular basis to ensure that your pool water is clear.
That said, many pool owners backwash weekly as part of their summer maintenance routine, often after they vacuum to collect the remaining particles that are often stirred up.
Use a vacuum or backwash the pool to remove the dead algae. Apply a mustard algaecide following the label directions. Allow the water to circulate for 24 hours. Use a pool vacuum or backwash the pool again to remove the remaining dead algae.
Backwashing is a filter cleaning process through your filter system that reverses the flow of water. Pool filters allow the removal of organic material by directing the water into a porous medium such as sand.
Lower the pH before shocking, 7.2 – 7.4 is best for shock efficacy. Dilute pool shock in a bucket of water for vinyl liner pools. Run the filter 24/7 until water is clear. Backwash only as needed.
The process of backwashing dislodges trapped debris and contaminants, flushing them out through your value's waste line or a hose that is connected to the pool pump. When the filter media is clean, the pressure gauge is lower and water can easily flow in and out of the system.
After a backwash, to get the amount of DE powder, simply take the recommended amount of DE powder for a new filter and multiply it by 0.8, or 80%.
After backwashing, new DE must be added to the filter. Add the entire amount of DE the filter recommends. If you see DE returning to the pool, vacuum it to waste, after it settles. The next time you backwash and recoat, decrease the amount by 1 pound.
Backwashing a sand or DE filter is a simple task. Shut off the pump, set the multiport valve or slide valve handle to the backwash position, roll out the backwash hose and turn the pump on again. Backwash for 3-4 minutes or until the water runs clear, then shut the pump off and return the valve to the filter position.
Do not drain pool or spa water into your septic system, as it may cause system failure. Make sure the water is not cloudy, the pH is neutralized, and the chlorine or other disinfectant residual is below 0.1 milligrams/liter (parts per million).
Swimming pool water contains chemicals, especially chlorine, that can harm your trees and landscape plants when water drains and floods the area. Too much chlorine can damage tree leaves and other delicate tissues.
Unless you have highly salt-tolerant yard plants, discharging saltwater into the yard may cause extensive damage; the soil retains the salts suspended in the water runoff. It is possible, however, to drain a saltwater pool into the yard using planned draining intervals.
Drain/Waste: Opting the drain or waste setting will remove pool water without forcing it through the filter. Backwash: This clears out any debris, dirt and other contaminants that may have accumulated on the filter.
Replacement sand for your sand filter typically costs around $25 per 50-pound bag, and your filter may require 100 to 600 pounds or more depending on the size and model. More than likely, you'll need about 350 pounds of sand for an average-sized inground pool filter.
If you do have this option, it is highly recommended that whenever you have algae, you will need to vacuum to waste. This option allows you to vacuum the algae up and send it out through the backwash line, avoiding getting algae into your filter sand.