Water cleanliness is a vital issue that takes center stage when you own a pool.
Many times it can feel like an endless cycle of water testing and topping up chlorine to keep the water it’s cleanest. However, all pools need a filter to remove the pollutants that your sanitizer kills.
DE pool filters are the top of the line choice to keep your pool water its cleanest.
We’ll discuss everything you need to know to find the best DE pool filter for your swimming hole.
Prefer to skip ahead?
Our Picks For Best DE Pool Filters?
We took a close look at the best diatomaceous earth pool filters available right now, then narrowed it down to only our top picks.
Best Overall (Recommended)
Best Grid D.E Filter
Hayward DE3620 ProGrid D.E. Pool Filter, 36 Square Foot, Vertical Grid
Best Quad D.E Filter
D.E Pool Filters Vs Other Filters
Pool filters come in three options: sand filters, cartridge filters, and DE (diatomaceous earth) filters.
While sand filters and cartridge filters are capable alternatives and cheaper options, DE filters are preferred for their ability to remove smaller impurities in pool water.
They use diatomaceous earth powder (an ancient form of microalgae) on a filter grid to grab pollutants as water passes through the filter on its way back to the pool.
DE Filter Pros:
- It’s the best pool filter, removing particles between 1 and 3 microns that are present in the water. In contrast, cartridge filters remove 10 microns, and sand filters remove 20 microns.
- Easy to install and DE powder is added through the skimmer
- DE powder is inexpensive at roughly a dollar per pound
DE Filter Cons
- Requires lots of maintenance. DE filters need to be disassembled after being backwashed. Deep cleaning the unit is also required once a year.
- Backwashing produces wastewater, and backwashing a DE filter (or sand filter for that matter) may be prohibited depending on where you live.
- Most expensive filter type, averaging $800 to $900.
Types Of DE Filters
There are two core types of pool DE filters you’ll come across.
Grid DE Filters
There are a few different styles of grid DE filters: finger, curved, and straight. They all work the same way, with DE powder coating the grid and contaminants sticking to the DE as water passes through the filter.
Finger DE filters have a grid system that resembles long vertical fingers, and there can be up to 100 of them arranged in a concentric circle.
Curved grid DE filters are the most common DE filter design. Using the same circular design, this filter has curved, flat grids made from polypropylene material. The curved panels come in different sizes and are layered on top of each other.
Straight grid DE filters use the same type of grid panels as the curved version, except they’re lined up one after the other (like Dominoes).
Reasons to get a grid DE filter:
- Some grid DE filters have a “bump handle” which allows you to shrug buildup off the grid. This reduces the pressure inside the filter, prolonging its cycle times and increasing its lifespan
- Straight grid DE filters can provide a more balanced flow inside the tank during both filtering and backwashing, allowing for lower filter pressure and higher flow rate.
- Curved grid DE filters are designed to conserve space inside the tank for water to flow
Quad DE Filters
Quad DE filters borrowed the design of quad cartridge filters and put their own unique spin on it.
This filter uses 4 cylindrical grids that resemble a cartridge filter, but are made from a thicker weave of woven polyester.
Reasons to get a quad DE filter:
- Longer filter cycles and increased flow rate compared to traditional cartridge filters
- The wider pleat design of these grids allow for easy cleaning. You can either backwash or hose them off without having to remove them from the tank.
Features You Need To Consider
Now let’s talk about the most important features to consider when it comes to choosing a diatomaceous earth filter for your swimming pool.
DE Filter Size
The filter you use for your pool needs to be the proper size. Incorrectly sizing it will result in an inadequately cleaned pool, and the filter’s grids will break down faster.
The filter has to be the same size as the pool pump you’re using. Even better if you can buy one larger than the pump.
While it’s common practice to turnover your pool water at least once per day, this only filters about 60% of the water. In order to get a full filtration of the water, turning it over 3 times is needed.
For example, if your pool is 20,000 gallons (which would be 1 full turnover), you should get a filter that can handle 60,000 gallons every 24 hours.
Calculating the flow rate would be 60,000 gallons, divided by 24 hours equals 2500 gallons per hour that need to be filtered. Dividing 2500 by 60 gives you a flow rate of 41.7 gallons per minute. If you were to only turn over the water once a day, your flow rate would be 13.9 gallons per minute.
You’ll have to consult the filters specs but you can use any filter that has a flow rate that meets or exceeds the gallons per minute your pool requires.
Filter Valve
DE filters are to be fitted with a multiport valve. These valves have several modes that allow you to perform a range of functions with the filter.
The most common modes are “Filter” (to filter the water), “Backwash/Rinse” (for cleaning the filter), and “Waste” (allows dirty pool water to be sent directly out a waste line).
Other modes you may come across are “Circulate” (to circulate the chemicals in the water while bypassing the filter) “Closed” (for not using the filter), and “Winterize” (for use when shutting the pool down for the winter months).
Cleaning Requirements
One of the knocks on DE filters is that they’re the most labor intensive when it comes to cleaning.
This is true, but once you do it a few times, it’s really not that big of a deal.
They can be backwashed but they also require you hose down the grids. Depending on the DE filter you have, you may have to fully remove the grid to do this. The filter’s pressure gauge will need to be monitored so you know when it’s time to perform this maintenance.
Also, some models will have a bump handle, which allows you to shake off debris and relieve the pressure that’s built up inside of the filter. This will give you a longer time between cleanings, and also prolong filter life.
Tank Construction
Pool filter tanks are made from metal or high quality plastics like ABS thermoplastic.
Decking out the filter in this type of plastic helps it resist corrosion, which is obviously important when buying a product that is subject to moisture 24/7.
Tanks also come in different different sizes, with some being large and round, while others are slim and tall. This is usually due to how big the tank needs to be for the pool, but it also helps if you are limited on space for your pool equipment.
Installation Difficulty
Installing a DE filter usually isn’t too hard.
Once the grids are set in place, you’ll have to hook it up to the plumbing as well as the multiport valve you’ll be using.
Sometimes, filters don’t provide the adequate fittings needed to connect everything, so make sure you have all the right pieces to connect the filter to your existing equipment.
Once everything is ready to go, DE powder is mixed with water and then poured into the pool’s skimmer. It then gets sent through the pool system, and the DE sticks to the filter’s grid, purifying water that passes through.
Other Things To Consider
Let’s finish on a few final things you should take into consideration.
Do You Have A Saltwater Pool?
Saltwater pools provide swimmers with less harsh water, but they aren’t immune to filth. Cleaning a saltwater pool works just like a traditional pool, as they still require a sanitizing chemical in the water, and a filter in the pool house.
There is no specific filter needed for a saltwater pool, but you’ll definitely get the cleanest water using a DE filter.
Do You Have An Above Ground Pool?
The majority of above ground pools use sand filters, most likely because above ground pool owners are usually on a tighter budget, and a sand filter fits that budget well.
It could also be that above ground pools (such as Intex pools) are smaller in size and don’t require as much cleaning.
Whatever the reason, a sand filter isn’t set in stone for these pools, and you can use any filter you’d like.
