Did you know that the Greeks in antiquity employed sand filters to keep the pools in their bathhouses clean?

The sand filter technology is that old, but don’t let that be a disadvantage. Even now, people use some of the finest innovations that were created centuries ago.

You might have inquiries like these if you’re a new pool owner or looking to upgrade your filtration system:

“A sand filter is what? How is a sand filter put to use? Is a sand filter system preferable than a cartridge one? What is the price of a sand filter?”

If you have any of these questions, don’t worry; we’ve got you covered.

We at River Pools produce fibreglass pools and operate one of the most popular swimming pool websites in the world. We attempt to cover the crucial maintenance subjects and pool items that they use on a daily basis because our focus is on educating pool owners and pool shoppers.

To assist you determine if a sand filter is the best option for your pool before making a purchase, we’ll go into great depth about them in this post. By the end, you ought to know more about sand filters, including if they’re a good choice, how much they might cost, how to maintain them, how they stack up against other kinds of filters, and other things.

Sand filter pools

How Do Sand Filters Work?

In essence, a sand filter is a tank filled with sand that is connected to your pool’s filtration system. The sand in the tank traps particles and trash that would otherwise return to the pool when the water flows through it. As a result, the water is cleaner and clearer.

Although glass or zeolite can also be used, #20 sand or mesh crystal silica is what most sand filters employ. Typically constructed of stainless steel, fibreglass, or plastic, the sand filter housing is strong enough to resist the high pressure needed to operate the filtration system.

What Functions a Sand Filter?

Sand filters work by forcing water under high pressure through the sand from the top of the tank to the bottom of the tank. The pointed edges of the sand grains capture dirt, debris, and human waste as the water trickles down. As the water cycles through, smaller and smaller particles are removed from it until the sand becomes too dense and needs to be cleaned, also known as backwashed.

How to Backwash a Sand Filter

The sand filter needs to be backwashed in order to clean the sand (manual or automatic). When you backwash your sand filter, water flows through the sand in the opposite direction, starting at the bottom and moving up to the top while collecting dirt and other particles.

When it reaches the top of the filter, it is then disposed of and does not go back into the pool, being sent to garbage. Backwashing is not a labor- or time-intensive process and may be finished in a matter of minutes.

The clean sand can resume filtering the pool water once the backwashing cycle is finished and the system has been cleaned.

How a Sand Filter Is Made

Continue reading if you want to learn exactly how a sand filter conducts water through the system since we’ll explain how the various sections of the filter are used. Please feel free to skip this section if you’d want to learn more about costs and upkeep.

The top of the tank is where the pool water enters the sand filter, and this is where the filtering process always starts. It follows that the water must be pumped to the top of the tank to start the filtering cycle if it arrives through a pipe at the side of the tank.

It can be compared to a fountain. Any path can bring water into a fountain, but it must always trickle down from the top layer.

The pool water is distributed uniformly across the sand bed by a distributor after it reaches the top of the sand filter tank.

After washing through the sand and leaving contaminants behind, the pool water enters the tank and flows to the laterals at the bottom. The lateral apertures are just big enough for water to flow through but not big enough for sand to get in and fill the pool.

Water used for backwashing emerges from the laterals at the bottom, moves through the distributors at the top and through the sand to the garbage.

The design and components of your sand filter will vary depending on the model.

What Is the Price of a Sand Filter?

The average cost of a new sand filter ranges from $300 to more than $1,000. Depending on size, inground pool sand filters can cost anywhere from $450 to over $1,200. Sand filters for above-ground pools are frequently less expensive, with starting prices in the $300 to $500 range.

Cost of Sand Filter Sand

Depending on the size and brand, your sand filter may need 100 to 600 pounds or more of replacement sand, which normally costs roughly $25 per 50-pound bag. For a typical-sized inground pool filter, you’ll most likely require 350 pounds of sand.

The cost of purchasing and assembling the sand filter itself, however, will be the biggest outlay.

Care for Sand Filters

Sand filters need some manual labour even though they are comparatively simple to maintain. Let’s examine what that would entail.

Cleaning of Sand Filters

When you backwash and rinse the sand filter, your sand will typically be cleaned. Although sand filter sand can last five to seven years, you will probably need to replace it roughly every three years. Because the sand tends to cause the waste in the tank to congeal, baquacil users might discover that they need to change it every year.

Pro tip: You can soak your sand in a filter cleaner to dissolve clumps if they form in your sand.

Replacement of Sand Filter Sand

Here are the procedures for a broad overview of how to replace the sand in your sand filter:

Remove the filter head and empty the tank of water.
Remove the old sand from the tank with a shop vac or a scoop.
Water should be added to the tank until it is halfway full.
As directed by your manufacturer, add sand filter sand.
Reattach the filter head and run a 30-second backwash of water.
Reset the filtration system to “filter” mode and check for leaks once more.
When replenishing your sand, remember to carefully follow the instructions. In particular, when replacing your filter sand, follow the manufacturer’s directions and put on the proper facial protection.

As you calculate how much sand to put to the filter and when you perform your backwash startup cycles, make sure to adhere to the guidelines.

When adding more sand, pay attention to how much freeboard you leave. Normally, it should be half the depth of the sand bed, but you may make sure by checking your user manual or looking for marks on your tank. (The maker of your sand filter should provide recommendations for how much sand to add to achieve a balanced sand-to-freeboard ratio.)

Replacement of Sand Filters: How Long Do Sand Filters Last?

If properly cared for and maintained, your sand filter can last anywhere from 15 years to 25 years or more. The majority of the time, you might need to repair gaskets and valves but not the entire system until several years later.

Make sure you obtain the correct size and install the new filter in accordance with the manufacturer’s instructions when it comes time to replace your sand filter with a new one. It’s equally crucial to make sure the new sand filter matches the flow rate of your pool pump.

How big of a sand filter do I require?

The size of the sand filter you require depends depend on the size and volume of water your pool can contain. For the majority of inground pools under 20,000 gallons, a sand filter with a diameter of 24 inches is used, whereas sand filters with a diameter of 36 inches are required for pools above 50,000 gallons (the largest size). A 24-inch to 30-inch tank is needed for pools with capacities of 20,000 to 30,000 gallons.

You can go up a size when calculating the appropriate size, but you should avoid going down a size since this can overload the system.

Which kind of pools benefit from sand filters the most?

A sand filter can be used to operate any inground pool, including fibreglass, concrete, vinyl liners, and other manufactured pools like container pools. Sand filter systems are also typically used by owners of above-ground pools (soft side and rolled wall).

As long as the filter size is matched to the size of the pool, the type of pool won’t ultimately determine what kind of filtration system you can have or how efficient it can be. To calculate an accurate turnover rate, be careful to account for the amount of hours you intend to run your filter each day.

Pre-purchase advice: Verify the filter’s “Turnover Capacity in Gallons” on the spec sheet.

What Does the Filtration Area of a Pool Filter Mean?

D.E. Filter versus Sand Filter

A D.E. filter is made up of a grid system that is covered in a white powder comprised of fossilised diatoms and seashell dust (AKA diatomaceous earth). These filters are capable of removing particles as small as 5 microns.

Although using crushed seashells and fossils to clean your pool may seem strange, a D.E. filter appears like any other pool filter and performs similarly. The way it operates and is maintained differs significantly.

To create a fine screen, diatomaceous earth is spread over a mesh. The D.E. collects dirt and debris as the water moves through the system, preventing it from entering the pool again. Similar to sand filters, D.E. filters require backwashing to remove particles and debris that have become lodged before continuing with regular filtering. Backwashing may be required multiple times. About every 90 days, the grids need to be manually cleaned.

Warning: Handling D.E. powder can be dangerous. While maintaining your filtration system, please use suitable face and eye protection.

Do DE Filters Work Better?

D.E. filters cost more than sand filters and require more maintenance. To maintain the filtration process, D.E. powder must also be fed to the system on a regular basis, in contrast to sand, which can last for years without replacement. On the other hand, compared to sand filters, they generate clearer water and capture considerably smaller particles.

Which is better: a sand filter or a cartridge filter?

Pool water is filtered and debris is captured when it passes through a cartridge filter, which uses pleated cloth wrapped around a cylindrical core. Cartridge filters are used in spas and pools; they are small and don’t require backwashing. They are very simple to maintain since, depending on the size, they simply need to be rinsed with a hose every four to six weeks. If you’ve been experiencing issues with algae, the filter may occasionally need to be soaked in a filter cleaning solution.

In our experience, cartridge filters work better than sand filters at removing contaminants and maintaining clear pool water. Additionally, cartridge filters are simpler to maintain than sand filters, collect smaller particles, put less strain on the pool pump, and don’t need to be backwashed. Plus, you won’t have to handle anything potentially harmful (sand, silica, zeolite, etc.).

Continue reading: Proper Filtration: The Key to Crystal Clear Water in Your Pool.

Get a Sand Filter, or Not?

With a basic understanding of what a sand filter is, how it functions, how much it costs, and how it compares to other filter types, let’s discuss the advantages and disadvantages you should take into account before purchasing one.

Pros and Cons of Sand Filters Pros:

Sand can survive for up to seven years before it needs to be renewed, but it will generally only last three.
Sand replacement is reasonably priced.
Sand filters require little upkeep.
Sand filters are widely used and simple to maintain.

Cons:

A sand filter’s pressure can be harmful. Always abide by the filter’s instructions booklet for your pool out of safety concerns.
Sand filters can’t remove particles as fine as cartridge and D.E. filters can, which results in less clear water.
The laterals in the sand filter are susceptible to breaking, which allows sand to enter the pool.

We hope that this information has assisted you in determining whether a sand filter is a viable solution for your pool. Before you depart, we’d want to part with some advice that each pool owner can use: Keep up with your pool upkeep responsibilities. Long-term appearance and performance of your pool and sand filter will be improved by how well you maintain them.

The best quote comes from Greek philosopher Aristotle:

“We become what we consistently do. Therefore, excellence is a habit rather than an act.”

Any queries or remarks? Please leave them in the form below, and we will respond as soon as we can.

For clients all around North America, River Pools produces top-notch fibreglass pools. If a fibreglass inground pool is something you’re thinking about buying for your house, you may browse our pool models to learn more about your fibreglass pool shape possibilities or use the button below to receive a bespoke quote. Try out our free pool pricing calculator right now for a quick estimate!

For clients all around North America, River Pools produces top-notch fibreglass pools. If a fibreglass inground pool is something you’re thinking about buying for your house, you may browse our pool models to learn more about your fibreglass pool shape possibilities or use the button below to receive a bespoke quote. Try out our free pool pricing calculator right now for a quick estimate!