Pool Sand Filter Size Chart - How Much Sand by Tank Size & Model

How Much Sand Does a Pool Filter Need?

How much sand a pool filter needs is set by the tank diameter, not by the size of your pool. Most residential sand filters take 100 to 350 lbs of #20 silica sand, which is two to seven 50 lb bags. The most common inground size, a 24 inch tank, takes 300 lbs, or six bags. The exact figure for your filter is printed on a label on the side of the tank, and that number overrides every chart online, including the ones below.

If you are still choosing a filter rather than refilling one, our pool filter size calculator turns your pool volume into a tank size, sand load, and bag count in one step.

Pool Sand Filter Size Chart: Sand by Tank Diameter

The amount of sand your filter needs is determined by the tank diameter, not your pool’s volume and not your pump size.

The most important step: check the label on your filter tank. The exact sand requirement is printed on a sticker on the side or back of every filter housing. It overrides any table you find online, including this one. Tank diameters are nominal, and there is variation between manufacturers.

If you are not sure your current filter is even the right size for your pool, our what size pool filter do I need guide walks through sizing before you buy media.

How Much Sand for a 16, 19, or 24 Inch Filter?

These three diameters cover the majority of residential filters, so here are the direct answers:

• 16 inch filter: 100 lbs of sand, which is two 50 lb bags. This is the common small above-ground size, like the Hayward S166T (Hayward’s own manual specifies 100 lbs).
• 19 inch filter: about 175 lbs of sand, so buy four 50 lb bags. Typical of mid-size above-ground filters and the Pentair Triton II TR-40, which Pentair rates at 180 lbs.
• 24 inch filter: 300 lbs of sand, which is six 50 lb bags. This is the standard inground size, including the Hayward S244T (rated 300 lbs by Hayward).

Diameters are nominal, so a tank sold as a 19 inch may measure 18.5 or 19.5 inches at its widest point. If your measurement lands close to one of these sizes, use the figure above and confirm against the sticker on the tank.

How to Measure Your Filter Tank Diameter

If there is no legible label and your model is unknown, you can still get the right quantity by measuring the tank yourself. You only need a flexible tape measure or a piece of string.

1. Measure the widest point of the tank body. Wrap the tape around the fattest part of the round housing to get the circumference, or measure straight across the top of the dome if the lid comes off.
2. Convert circumference to diameter if you measured around the tank. Divide the circumference by 3.14. A tank measuring about 75 inches around is roughly a 24-inch diameter tank.
3. Round to the nearest size in the table above. Filter tanks are sold in nominal sizes (16, 18, 19, 21, 24, 27 inch). If your number lands between two sizes, round down and confirm against the manual, because a slightly underfilled tank is safer than an overfilled one.
4. Measure diameter at the sand fill point, not the base. Many tanks flare out at the bottom for stability, so measuring near the base gives a number that is too large.

Once you have the diameter, read the sand requirement straight off the quick-answer table. Write the figure on the tank with a paint pen so you never have to measure again.

Sand Filter Size Chart by Brand and Model (Hayward, Pentair, Intex)

These figures come from the manufacturers’ own manuals and spec sheets (Hayward ProSeries and Pentair Triton II documentation), so if a generic diameter chart disagrees with this table, trust the model row.

Two models generate the most confusion. The TR100 is the Pentair Triton II TR-100, a 30 inch tank that takes a full 600 lbs of sand (twelve 50 lb bags) per Pentair’s spec sheet. The TR140 is the Pentair Triton II TR-140, a 36 inch tank that takes 925 lbs (nineteen 50 lb bags). Both are much larger than their model numbers suggest, and they are often searched as Hayward models. Hayward’s ProSeries line runs smaller: the 24 inch S244T takes 300 lbs and the 27 inch S270T takes 350 lbs.

If your model is not listed, measure the widest part of the tank with a tape measure or check the owner’s manual, then read the sand amount off the tank diameter chart above. The same chart logic applies to above-ground filters: quantity follows tank diameter regardless of where the filter sits, so a 16-inch above-ground tank takes the same 100 lbs as any other 16-inch tank.

Above-Ground vs Inground Sand Quantity

There is no separate sand figure for above-ground and inground filters. Both use the same rule: quantity follows tank diameter. The difference is that above-ground filters tend to run smaller, so the typical bag count is lower.

• Above-ground filters are commonly 16 to 22 inches in diameter, so most need 2 to 4 bags (100 to 200 lbs).
• Inground filters are commonly 21 to 30 inches, so most need 4 to 12 bags (200 to 600 lbs).
• Small portable pump-and-filter units from Intex (Krystal Clear) and Bestway (Flowclear SX) are the smallest of all. Their tanks hold only 6 to 50 lbs depending on the model.

For the small Intex and Bestway sand pumps, follow the printed figure on the unit rather than the residential table. As a rough guide, a Krystal Clear SX2100 (10 inch) takes about 20 lbs, an SX2800 (12 inch) takes about 35 lbs, and a larger SX3000 takes about 50 lbs. A single 50 lb bag covers most of these units with sand to spare, so one bag is usually all you buy.

How Many Bags of Sand Do I Need?

Most pool filters need two to seven bags of sand: 2 bags for a 16 inch tank, 4 bags for a 21 inch tank, 6 bags for a 24 inch tank, and 7 bags for a 27 inch tank. Pool filter sand ships almost exclusively in 50 lb bags, so converting any sand requirement to a bag count is one step: divide the pounds by 50 and round up to the next whole bag.

Worked example: your tank label calls for 175 lbs of sand. 175 divided by 50 is 3.5, which rounds up to 4 bags. Pour three full bags, then add from the fourth until you hit the fill line at 2/3 of the tank, and keep the remainder for top-ups.

Buy one spare bag beyond the calculated count. Some sand always spills during the pour, and a partial bag on the shelf beats a second trip to the store mid-job.

How Much Sand Costs to Fill a Filter

A 50 lb bag of #20 pool filter sand costs about $12 to $15 at most pool stores and online. Because the price scales directly with bag count, the total media cost is easy to estimate from the table above.

Sand is the cheapest part of owning a sand filter. It lasts several years, so the cost works out to only a few dollars per season. For a full picture of replacement intervals see how long does pool filter sand last and how often to change pool filter sand.

You can compare current bag prices for #20 pool filter sand on Amazon before buying locally, since shipping a single heavy bag sometimes costs more than picking it up.

The Fill Level Rule: 2/3 Full, Not Full

Sand filters should be filled to approximately two-thirds of the tank’s capacity, never to the top.

The upper third of the tank serves as a water reservoir above the sand bed. During the filtration cycle, water enters the top of the filter and pools in this space before being drawn down through the sand. Without this space:

1. The filter loads with debris faster (less volume per filtration cycle)
2. Backwashing is less effective (the reversed flow cannot agitate the sand properly)
3. In extreme cases, the multiport valve cannot seat correctly

Most sand filters have a fill line marked inside the tank. If yours does not, 2/3 full is the correct target.

Alternative Media Quantity Conversions

You do not have to use silica sand. The two common alternatives change the quantity you buy, so plan the conversion before you order.

• ZeoSand and other zeolite media use roughly 50% less media by weight than sand. A tank that needs 200 lbs of sand needs about 100 lbs of ZeoSand. It traps finer particles and can extend backwash intervals. You can check current pricing for ZeoSand zeolite media on Amazon.
• Pool filter glass is added at a 1:1 ratio by volume with sand, but glass is less dense, so each bag covers more tank for less weight. A 200 lb sand tank typically takes about 175 lbs of glass media. Glass resists channeling and can last longer than sand.

Both media drop straight into a standard tank with no hardware changes. For the full media comparison see our pool filter sand alternatives guide, our pick for the best pool filter glass media, and the broader pool filter balls vs sand comparison.

How Many Bags to Buy and Buying Tips

Buying sand is simple once you know the bag count, but a few habits save a second trip.

• Buy one spare bag. Bags settle and a little spills during pours. Having one extra 50 lb bag on hand means you never stop a job halfway because you came up 10 lbs short.
• Check the grain size on the label, not just the word sand. You want #20 grade silica at 0.45 to 0.55 mm. Bags simply labeled silica or play sand are the wrong product.
• Mind the shipping weight. Online sand is heavy and shipping a single bag can cost as much as the sand. If you need four or more bags, online bulk pricing often beats the store. If you need only one bag, local pickup is usually cheaper.
• Store leftover sand dry. Sealed and kept off a damp floor, leftover #20 silica keeps indefinitely for your next top-up or change.

What Grain Size Should Pool Filter Sand Be?

Pool filter sand must be #20 grade silica with an effective grain size of 0.45 to 0.55 mm. That number matters more than the brand on the bag.

The grain size is a physical fit for the filter’s internals. The laterals at the bottom of the tank have slots sized to hold back 0.45 mm grains while letting water pass. Finer sand, like play sand at roughly 0.2 to 0.3 mm, slips through those slots and blows back into the pool as a cloudy plume every time the pump runs. Coarser sand does the opposite: the gaps between large grains are too wide to trap fine debris, so water passes through nearly unfiltered and stays dull no matter how long the pump runs.

Check the printed grain size on the bag before buying. If it says #20 silica or 0.45 to 0.55 mm, it will work in any residential sand filter. Our what type of sand for pool filter guide covers the grades in more detail, and our best pool filter sand roundup lists bags we have verified meet the spec.

What Sand to Buy

The correct media for virtually all residential pool sand filters is #20 grade silica sand with a grain size of 0.45 to 0.55 mm. It is sold specifically as pool filter sand at pool supply stores and online.

For a reliable, widely stocked option we recommend HTH #20 pool filter sand on Amazon. It is a consistent 0.45 to 0.55 mm #20 silica with a clean white colour, sold in standard 50 lb bags that match the bag counts in the tables above. For more tested options see our roundup of the best pool filter sand.

Do not use:

• Play sand (wrong grain size, too fine)
• Construction sand or river sand (contaminated, wrong size)
• Beach sand (irregular grain, organic contamination)
• General-purpose silica sand (check the grain size, many are too coarse)

See our full guide on what type of sand for pool filter for the complete breakdown of media types including ZeoSand and filter glass alternatives.

If You Are Replacing the Sand

When changing sand, you will need the tools and steps in our how to change pool filter sand guide. The most common mistake when replacing sand: not filling the tank halfway with water before adding the new sand. The water cushion prevents the laterals from cracking on impact, a repair that costs more than the sand itself.

Related Guides

• How Much Sand for an Intex Sand Filter for Intex SX-series model amounts
• How to Change Pool Filter Sand for the full step-by-step replacement procedure
• What Type of Sand for Pool Filter? for #20 silica vs ZeoSand vs filter glass
• How Often to Change Pool Filter Sand? for when replacement is needed
• How Long Does Pool Filter Sand Last? for expected media lifespan
• Pool Filter Sand Alternatives for ZeoSand and glass media options
• Sand Filter Complete Guide for all sand filter topics in one place