When added to your pool filter, DE powder functions as a sponge, allowing water through but straining out even the tiniest particles of dirt and debris. It's essential to replace DE powder in your pool filter regularly to keep your swimming pool from getting cloudy.
Do not operate your filter pump without having the D.E. powder coating the grids, or you will see the filter pressure rise very quickly, and if left in this manner the grids can collapse or the fabric can become clogged or damaged. As the pressure gauge on a D.E. filter increases, flow rate decreases.
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).
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.
Pros: The DE filter has the advantage of filtering the water to the smallest particle size (2-3 microns) and will keep the water cleaner than a sand filter or cartridge filter. This can translate to less pump run time and less sanitizer needed to keep the water clean and clear.
When determining which pool filter works best for your pool, consider the types of debris your pool collects. A DE filter will work better on smaller particles while a cartridge filter will work more efficiently with larger types of debris.
Small amounts of DE can be added to a sand filter after each backwash to improve the filtering. The first time you use DE, you need to figure out how much DE to add to your filter. After the first time, you can simply mix the full amount of DE with water in a bucket and pour that slowly into the skimmer.
For New Filters or Full Cleaning
Eventually, of course, you'll have to replace the powder with a complete clean of your filters. You should do a total DE filter cleaning one or two times per year, as long as you are backwashing your filter every one to three months.
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.
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.
The 3 main types of filters that can be used with your salt system are sand, cartridge and diatomaceous earth or D.E. When considering each type of filter for your salt water pool they each have their distinct advantages, ideal application and disadvantages.
Common D.E. Filter Problems:
DE Blow-Back: If DE powder is coming into the pool, you may have torn filter grid fabric. Or, you could have a cracked top manifold, or missing air bleeder. The standpipe o-ring could be missing, or the filter valve could be allowing some DE powder to bypass the filter as you add it new.
This leaves your pool a cloudy, muddy-looking mess. Luckily however, the powder usually sinks to the bottom of the pool. The only way to remove the earth from your pool is to vacuum the pool with the filter release valve open. This will allow the earth to flush from the filter.
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).
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.
Although DE powder is used for filter grids, it can be added to sand filters. When the powder is added to the sand, the sharp edges of the DE powder enhance the filtering process of the sand by capturing tiny dirt particles during the filtering process.
Whether you have a sand, DE, or cartridge filter, you'll need something to sanitize it. Chlorine is effective, as is a salt system. Swimming pool salt systems turn the salt into chlorine, which means you have to use some form of chlorine with any sand filter.
The dead algae is likely too fine to be vacuumed through your sand filter, therefore owners of sand filters must vacuum on the waste setting. Cartridge filter owners can vacuum up the dead algae but need to clean the filters thoroughly after doing so.
Cartridge elements are a non-woven material that the DE can wedge itself into and be VERY hard to clean off. We generally don't recommend it as it will permanently clog your cartridge filter and cause higher pressure drop long term (until you replace the cartridge).
The food-grade type is considered safe for human use and consumption because it is low in crystalline silica. However, the filter grade form is rich in crystalline silica, making them very toxic to human use. You also need to handle diatomaceous earth with care as not to inhale it.
Chemically, it is safe to swim. You will need circulation in the pool to introduce chlorine...... keeping it sanitary and algae free.