You should backwash your DE pool filter about once a month during pool season. In addition to the regular schedule, you'll want to perform additional backwashing if: You've been running your pool filter for 48 hours straight. This can cause a pressure build-up, even if the filter grids look clean.
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.
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.
Adding too much DE to your pool may cause multiple negative results. These ramifications include a clogged skimmer, turning the pool cloudy, reducing the circulatory pressure in the pool and putting too much work on your pump that may result in eventually breaking the pump.
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.
If you do not add enough DE to your filter, then the grids are not totally coated with DE and the dirt that goes into your filter will attach itself right to the fabric on the grids and will not backwash off. This will cause your filter to short cycle (go very short times between backwashing).
Run your filter 24 hours a day and backwash 3 or 4 times a day for quickest results. Green or cloudy water will quickly clog a filter, therefore you may have to backwash your filter many times a day until the pool clears. THIS IS NORMAL ! Remember, you cannot over-backwash a pool filter.
Diatomaceous Earth (D.E.) Filter
The D.E. needs to be replenished once the filter is turned back on. Every three months the filter should be taken apart, the grids should be hosed off, and visually inspected for any rips or tears that will cause D.E. to blow back into the pool.
However, if you can't find a suggestion from the manufacturer, you can use a simple rule of thumb: For a full clean or new filter, add one pound of DE powder for every 10 square feet of the filter. So, a 48-square-foot filter will need about five pounds of DE powder.
Your filter may be clean and normal at 9-10 psi, but your neighbor's filter gauge could run higher, and be clean at 15-16 psi. Some systems with very low resistance can run very low pressures, barely registering, while other filter systems can run quite high, pushing 30 psi when the filter becomes dirty.
Knowing When to Replace Grids
Those with a DE filter should be opening up their filter and cleaning the grids every three months or more often. DE filter grids can last for four or five years with proper care.
Can You Backwash Too Much? If you backwash your pool too much i.e. time duration and/or close frequency then yes you can cause a lot of problems. Some problems that can arise from backwashing your sand pool filter too much are: Loss of water – 500+ litres of water can be lost in each backwashing cycle.
The most common reasons why a cartridge, sand, or DE filter's pressure rises quickly, even after cleaning or backwashing, is a clogged or blocked filter, algae or old filter elements. If any of these things are wrong, the pressure can rise rapidly in minutes, hours or days.
After the hose fills with water, backwash your sand filter for 2 - 3 minutes, or until water runs clear. Shut off the pump motor and push the T-handle back down into locked position. Turn your pump back on and note the lower pressure.
Turn the lever to RINSE, start the pump and rinse for about 15-30 seconds. Stop the pump and turn the lever to FILTER. This is the normal operating position. Close the drain outlet valve and start the pump.
You should backwash your DE pool filter about once a month during pool season. In addition to the regular schedule, you'll want to perform additional backwashing if: You've been running your pool filter for 48 hours straight. This can cause a pressure build-up, even if the filter grids look clean.
DE Filter Grids Clogged with Oil
Much is brought in on the wind, or dragged in by swimmers. Pool lubricants and some gel type pool clarifiers can add oils to your pool, which eventually is trapped in the filter grids.
Those with DE filters are probably extremely happy with the quality of water that a DE filter creates, but there comes a time when you will need to replace the filter grids. This is usually after 7-10 years of hard work. The filter grids may develop holes or become unstitched and clogged with oils and minerals.
A DE Scoop is specially designed to measure DE powder and 1 scoop is equal to 1/2 lb. of DE powder. To determine how many scoops or coffee cans of DE your filter requires take your filter square footage and divide by 5 (this would be after a full cleaning).
Rinse runs water in the same direction that normal filtering does. 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.
Shock the pool with chlorine every day until all the green is gone (possibly 3 to 4 days). 2. Run the filter 24 hours a day and backwash every day until the green and then cloudiness is gone (usually up to 7 days, sometimes as long as 2 weeks depending on the filter). 3.