Cleaning a Diatomaceous Earth (D.E) Filter


EP Minerals has produced Celatom diatomite especially for use in diatomaceous earth (DE) swimming pool filters. To obtain the best water clarity in your pool or spa and the longest time between DE changes, please follow the steps below. Also, please read and follow the instructions provided by your filter manufacturer.


Before adding Celatom DE, visually inspect the screen-like filter elements inside your filter, to make sure they are clean and free from tears and gaps. Filter elements which are dirty or torn can cause problems with your water clarity and reduce the efficiency of the Celatom DE. If the elements are dirty, wash them thoroughly and re-assemble the filter unit. If they are torn, please consult your filter manufacturer's instructions for repair or replacement.


To add Celatom DE to your filter, slurry the DE (see table) into a pail of water, and stir until the DE is well mixed. With your pool circulation pump operating in the normal filtering mode, pour the DE mixture into the pool skimmer.

When you add Celatom diatomaceous earth (DE) to your pool, the pump circulates it into your filter, where the DE forms a thin layer on the surface of the filter screens. This layer of DE does the actual filtering of impurities from your water. The screens are simply there to support the layer of DE. The recommended amount of DE is sufficient to trap the dirt and solids present in your pool. Using too much or too little DE could reduce your water clarity or reduce the time between flushing and re-charging the DE.


After adding the DE, continue to operate your circulation pump using your normal cycle as recommended by the filter manufacturer or installer. As the pool water is circulated through the filter, solid particles and body oils are removed by the DE layer, and the crystal clear water circulates back to your pool. Over time, usually several weeks or months, the DE will become clogged with the impurities that have been removed. The filtration cycle is complete when you note a significant drop in the flow rate and an increase in the pressure, which can be seen on the filter pressure gauge. Please consult your filter equipment operating manual for more information.

The length of the filtration cycle will vary depending on the amount of solids and body oils that have been removed. An increase in the number of swimmers or debris in the pool will cause the filter pressure to build up more rapidly. If you expect an increase in the number of swimmers or dirt in the pool, you can extend the cycle length by adding a small amount of additional DE into the skimmer, mixing it first with a pail of water and pouring it into the skimmer as in Step 2. Do this just before the increased use occurs, if possible.


When the filtration cycle is complete, as indicated by high pressure on the filters pressure gauge the filter must be backwashed or cleaned to remove the used DE. Backwashing the filter involves reversing the water flow and/or hand washing (hosing) down the filter elements. Continue the backwashing or cleaning procedure until the waste water runs clear or the filter elements are visibly clean. Proper maintenance and thorough cleaning of your filter are necessary to obtaining clear water and long filtration cycles. Consult your filter manufacturer's operating instructions for complete backwashing and cleaning procedures.

The used DE and waste water can be pumped to the sanitary sewer, or the DE may be separated from the water, using separation tanks or filter socks, and disposed of in the garbage or spread in your lawn or garden and tilled into the soil. DE is commonly used as a soil amendment and is beneficial for most plants.