Filters : D.E.
DE Filters
- The Diatomaceous Earth (DE) filter contains filter elements that are either curved grids or Flex tubes (long finger-like tubes). They are covered in a fabric on which the DE forms a coating. The DE acts as a filter by permitting water to filter through the DE and leave the impurities behind. The DE filter has the ability to filter out microscopic particles.
Why does my filter pressure rise very quickly, even after backwashing?
- D.E. filters filter the water down to 1-3 microns, every time the water passes through the filter. Maintain a balanced clear pool and this will reduce incidents of rapid pressure rise. One possibility is that the filter grids or Flex tubes are clogged with minerals or oils. You should clean your grids once a year, or season, with a degreaser and if needed an acid bath. Minerals and oils embed themselves in the fabric of the filter and reduce the available surface area used for filtering.
- If too little DE is added during pre-coat, debris and particles will embed in the fabric. Cleaning with a high-pressure hose, NOT A POWER WASHER, may be needed to remove the grids. If cleaning does not work, then replacement is the only option.
Will backwashing thoroughly clean my DE filter?
- When a DE filter is properly backwashed you will be removing about 80-90% of the DE. Remaining DE may be clumped in the corners of the filter or caked in the middle. This is common. 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. This will avoid DE going back into the pool.
- The only way to remove the entire DE is to disassemble the filter. The next time the filter is disassembled and cleaned, pre-coat with the entire quantity of DE.
Remember, the filter should be taken apart and cleaned at least once a year.
How do I add DE and how often do I need to change my DE?
- DE is added through the skimmer with the pump running. Each filter has a different requirement of DE. At initial start up or after a thorough cleaning, the filter will need to be pre-coated with DE. The filter label will state the amount of DE required. Start the pump and once the pump is fully primed, measure the DE using a DE scoop, part # EC10SC. Slowly add the DE into the skimmer. The pump will draw in the DE and send it into the filter, where it coats the grids or Flex tubes. Once all the DE is added, take a reading of the filter’s pressure gauge. This is the clean starting pressure of the filter.
- When the pressure rises 8-10 PSI above the starting pressure, it is time to backwash or clean the filter. After the filter is backwashed or thoroughly cleaned, by taking it apart and hosing it out, you will need to pre-coat the filter again with the entire amount of DE stated on the filter label.
Why is DE leaking into the pool?
- There are only a handful of reasons DE is leaking into the pool. They vary depending on which DE filter you have.
(a) Vertical Grid:
(1) Too much DE was added.
(2) Tear in the fabric of the Grid
(3) Crack in the top manifold
(4) Bad o-ring on the standpipe (the pipe the DE cluster sits on)
(b) Perflex “Bump” Filter.
(1) Too much DE
(2)Tear in the fabric of the fingers
(3) Bad diaphragm gasket
(4) Cracked tube sheet(s)
(5) Loose or missing tube sheet bolts
(6)Bad o-rings on the bump shaft
How do I backwash my DE filter?
- Vertical Grid: When the filter pressure rises 8-10 PSI over the clean starting pressure, the filter must be backwashed. Turn off the pool pump. Rotate the multiport valve to backwash position or slide the slide valve up. When the pump is turned on, the dirty DE and water will flow out to waste. Once the water runs clear, turn off the pump. With a slide valve, push the handle down and start the pump. Once the pump is primed, add the required DE.
If using a multiport valve, rotate the handle to rinse. Turn on the pump and let water flow for 20-30 seconds, cleaning out the plumbing lines. Turn off the pump and rotate the valve back to filter. Turn on the pump and once primed add required DE.
- Perflex “Bump”:
Perflex filters are unique because they cannot be backwashed. Once the filter pressure rises 8-10 PSI over clean starting pressure, it is time to bump the filter to regenerate the DE. Turn the pump off and grasp the bump handle. Slowly raise the handle then firmly push it down. Repeat this action 3- 4 times. Inside the filter the Flex tubes are being raised and lowered, shaking the DE and debris off the tubes. The DE is then sitting on the bottom of the filter.
When the pump is turned on, DE will recoat the tubes. The filter pressure will not drop to the original starting pressure, but will drop lower then the previous reading. (Example: the original starting pressure was 10 PSI. You “bumped” the handle when the pressure reached 20 PSI. After the bumping, the pressure dropped to 13 PSI.)
The pressure reading after bumping is the new starting pressure. When the pressure goes 8-10 PSI over this, the filter will need to be bumped again.
When there is no pressure drop after bumping or the pressure rises very quickly after bumping, the DE will need to be drained and replaced.
To replace DE turn off the pump, bump the handle to shake DE off of the tubes and open the drain valve. The pump can be turned on to help expel the dirty DE, but it should be for no longer than a minute. A jet-action cleaning wand can be used to remove any remaining DE.
Once a year, the filter should be taken apart and thoroughly cleaned.
lters are unique because they cannot be backwashed. Once the filter pressure rises 8-10 PSI over clean starting pressure, it is time to bump the filter to regenerate the DE. Turn the pump off and grasp the bump handle. Slowly raise the handle then firmly push it down. Repeat this action 3- 4 times. Inside the filter the Flex tubes are being raised and lowered, shaking the DE and debris off the tubes. The DE is then sitting on the bottom of the filter.
When the pump is turned on, DE will recoat the tubes. The filter pressure will not drop to the original starting pressure, but will drop lower then the previous reading. (Example: the original starting pressure was 10 PSI. You “bumped” the handle when the pressure reached 20 PSI. After the bumping, the pressure dropped to 13 PSI.)
The pressure reading after bumping is the new starting pressure. When the pressure goes 8-10 PSI over this, the filter will need to be bumped again.
When there is no pressure drop after bumping or the pressure rises very quickly after bumping, the DE will need to be drained and replaced.
To replace DE turn off the pump, bump the handle to shake DE off of the tubes and open the drain valve. The pump can be turned on to help expel the dirty DE, but it should be for no longer than a minute. A jet-action cleaning wand can be used to remove any remaining DE.
Once a year, the filter should be taken apart and thoroughly cleaned.
NOTE: Take a reading of this new clean starting pressure, so you have a reference point for the next backwash cycle. Water may need to be added to the pool to replace the backwashed water.