How To Maintain a Pool Sand Filter?
So you’ve been considering purchasing a swimming pool. Great! There’s a lot to consider when making the decision. What type of pool do you want to get? What kind of features and add-ons would you like? One of the more technical aspects you may not yet have considered at this stage is what type of filter you’d prefer: diatomaceous earth, cartridge, or sand. Welcome back to our series on pool filter maintenance. In this article, we’re going to talk about sand filters, another highly popular and reliable filter type.
The purpose of a pool filter is to remove debris from the pool, and all three filter types will perform this basic function, albeit slightly different from one another. As a potential pool buyer, you’re probably wondering what exactly the differences are as far as cost (insert cost comparison article) and maintenance go. Will I have to replace the filter every few years? What kind of filter media is best? What is backwashing? These are all natural questions to have. At Royal Pools G2 Landscaping we’ve installed and maintained all three filter types in our 26 years of business, and we’ve learned a thing or two about sand filters that we want to share with anyone considering purchasing.
What Is A Sand Filter? How Does It Work?
A sand filter is a filtration system comprised of a round shell (typically comprised of plastic, fiberglass, or stainless steel) that contains sand. As water passes through the filter back into the pool, the sand within the filter catches debris, preventing it from returning to the pool. The sand in these filters is generally silica sand or some type of glass sand media.
Sand filters work fairly simply. Water is sucked into the filter at the top of the shell and trickles through the sand to the bottom, during which debris in the water is trapped by the sand. The water is sucked back up into the laterals at the bottom of the filter shell through a tube that returns the now clean and debris-free water into the pool. This process is happening constantly as the pull is running and the filter is on filter mode.
Sand filters can filter debris around 20-40 microns (micrometer: 1/1,000,000 meters) in size. Whereas cartridge filters can filter debris around 10-20 microns in size, and diatomaceous earth filters can filter debris as small as 5 microns. All this to say, a sand filter will not eliminate debris as small and unnoticeable as what a cartridge or D.E. filter could eliminate.
Weekly Maintenance
Maintaining a sand filter on a week-to-week basis is very easy. Just monitor the PSI levels on the pressure gauge and ensure that the PSI is in the ideal range, usually somewhere between 5-20 PSI. How often you backwash the pool will depend on a couple of factors like the pool size and regular swimmer load. A sand filter should be backwashed at least once a month.
If you’re someone who would like to manually vacuum their pool on a week-to-week or bi-monthly basis, we recommend always backwashing your sand filter upon completion of the vacuuming to remove any debris buildup from the filter. If you’re going to get the pool floor spotless, might as well get the filter spotless as well!
Backwashing
As previously stated, backwashing and rinsing are the most important maintenance precautions you can take with sand filters. After collecting so much debris and unwanted properties from a pool, the sand in a sand filter will start to build up in pressure. The way to determine when to backwash your filter is by monitoring the pressure on the pressure gauge. When the pressure is 8-10 PSI over recommended levels, it is time to backwash the pool.
Backwashing is simply the process of reversing the flow of water so that it comes out of the laterals at the bottom of the filter, traveling up through the sand and catching all the unwanted particles and debris. When the dirty water reaches the top it is pushed out of the filter through a backwash line.
Backwashing can be done by shutting the pool pump off and changing the filter’s current mode from filter to backwash. Most sand filters are outfitted with a clear glass eyeball at the top of the filter that is filled with water during the backwash. When you start backwashing, you’ll notice the water turns cloudy or discolored. Backwash until the water looks clear, and you’re good to go.
After the backwashing process, it is always recommended to run the filter in the rinse mode for 30-60 seconds, expelling any leftover dirty water from the backwash out of the filter.
Sand Filter Lifespan
Similar to cartridge filters, after a certain amount of time, your sand filter media, in this case, the actual sand, will need to be replaced. If you’re lucky you can make filter sand last up to seven years, but generally speaking filter sand will need to be replaced every 3-5 years.
Conclusion
A sand filter will perform all the best functions of a pool filter regardless of pool type or size. The biggest downside to these filters is the little bit of maintenance required throughout the swim season and the long-term costs of new sand. We recommend sand filters to new pool owners for their simplicity and ease of use. We hope this article helped you determine if a sand filter is the right filter for you. For more information on sand filters as well as cartridge and D.E. filters, check out the articles below. Dive into our learning center for more educational content on all things pools and landscaping. Check out these videos/articles below to learning:
How To Maintain A Pool Cartridge Filter?
How To Clean Your Swimming Pool Cartridge Filter
Top 5 Chlorine Alternatives For Pools!
Written By Logan Edgemon