Pool Filter Sand Alternatives

FilterGlass close-up

Even though they are called sand filters, you don’t need to use sand for the filtration media in your sand filter.

If you decide you’d like to make a change you can have product on hand so you are ready to open the pool as soon as the weather cooperates.

If you have had a sand filter for a while, you are most likely already aware that the standard filter media to use is called #20 silica sand. This sand is about .45-.55 mm in size and is capable of filtering out debris about 20-40 microns in diameter. As a reference, the diameter of the average human hair is 60-80 microns. Assuming you have good eyesight, particles that are smaller than 30-40 microns are generally no longer visible to the naked eye.

ZeoSand and FilterGlass are two alternatives to standard silica sand, and each of them can generally increase the filtration capacity of your sand filter to less than 5 microns, which is comparable to the filtration capability of a DE filter.

FilterGlassfilter-glass filter sand alternative

FilterGlass is made of finely crushed recycled glass. The glass particles are smooth to the touch, so no worries about adding sharp, jagged glass into your pool filter. Each piece is uniquely shaped (known as amorphous), making it less likely to “channel” as silica sand can over time. FilterGlass has a slightly negative electrical charge that allows it to hold fine, positively charged particles such as iron and manganese.

  • FilterGlass filters out particles as small as 2-5 microns.
  • Excellent at removing metals like iron and manganese.
  • Removes skin cells, blood cells and 70 percent of all bacteria.
  • Backwash about 75 percent less, saving water and chemicals.
  • Use 20 percent less FilterGlass than you would silica sand.
  • Compatible with all sanitizers, clarifiers and metal removers.
  • Does not require backwashing after adding FilterGlass.

zeo-sand pool filter sand substituteZeoSand

ZeoSand is made of 100 percent natural zeolites (minerals found in volcanic rock). The zeolite particles have a three dimensional honeycomb structure that gives a cubic foot of ZeoSand about 100 times the surface area as a cubic foot of sand, allowing smaller particles to be trapped.

Because of its lower density and the way that zeolites lay against each other, you’ll use about half as much ZeoSand by weight than regular filter sand.

  • ZeoSand filters out particles as small as 2-5 microns.
  • Traps ammonium ions responsible for chloramine formation.
  • Lasts longer than sand and requires 50 percent less backwashing.
  • Use 50 percent less ZeoSand than you would silica sand.
  • Removes and kills bacteria with a molecular sieving process.
  • All natural and environmentally friendly.

Which Should You Choose?

FilterGlass and ZeoSand will each remove particles under 5 microns in size, so they will both dramatically improve the clarity of your pool water over silica sand. However, as you can see above there are some differences between the two, which may make one a better choice than the other depending on your needs.

If you use well water or find yourself constantly battling metal stains, then perhaps the FilterGlass would be a better choice due to its enhanced ability to remove metals from the water.

If you find that you need to shock frequently, perhaps it’s worth trying the ZeoSand to benefit from its ability to trap chloramine-causing ammonia. This will reduce the need to shock the pool and reduce red eyes, itchy skin and that chlorine smell.

Both of these pool filter sand substitutes require much less backwashing than regular sand, though the FilterGlass will require the least. Less backwashing means less pool water and chemical waste and more time on your hands!

zeo-sand-closeup

Standard silica sand costs about $10-15 per 50-pound bag. You generally can obtain this product at a local pool supply or hardware store. Most companies (including In The Swim) do not sell the sand online because the cost to ship the sand is generally just as much, if not more, than the sand itself.

There is no doubt that both the FilterGlass and ZeoSand are both significantly more expensive per 50-pound bag (current prices are $40-$45 per 50-pound bag), but when you consider you will use less of the product (especially in the case of ZeoSand where you use half has much) and will likely use much less clarifier and other chemicals, they are still attractive from a cost standpoint.

36 thoughts on “Pool Filter Sand Alternatives

  1. Ernest V Garcia

    if you are performing a backwash flush of debris from your sand filter, make sure you move the lever to the rinse option after the backwash to help eliminate the contaminants reentering your pool

  2. I have an above ground pool that is 27000 gallons. I bought a SD80 sand filter and i have a 2 horse pump. This is my second year and I find when I vacuum the algea blows back in through the return or if I turn my pump on high it does the same thing! Would changing to zeosand catch the smaller particles better?

    • Hi Amy, it is somewhat normal for a sand filter to experience blow-back. It could be however, that the pump is too powerful for the filter size. Your pool needs about a 60 GPM flow rate, and depending on the pump, it could be pumping much more, which results in poor filtration, and just pushes the dirt right thru. If you have a variable speed pump, optimize the speed for about 55-65 GPM, and try not to exceed that rate. Zeosand may not be an improvement. When vacuuming the algae, fill the pool full, and vacuum to waste. You may also benefit from using Clarifier regularly, or may want to look at the Slime Bag product.

      • I had the same pump when we used a cartridge filter and i never had these problems. Do think I need to just go back to using that filter system instead?

        • HI Amy, I just looked up the Design Flow Rate for the SD80 filter, and it is 75 GPM. Not sure what pump you have, but you can look up the Flow Chart, and see what flow rates it is capable of, might be more than 75 GPM, which would cause the issue.

  3. Brenda carrigan

    Hi I am setting up my sand filter and I want to use zeosand instead of the #20 sand, do I fill my sand filter up to the fill line with the zero sand?

    • Hi Brenda, you could fill it up to normal level if you want, but ZeoSand instructions are that one 50 lb bag of Zeosand is equal to 100 lbs of regular filter sand, so you only need to use half as much, but you can use more if you want.

  4. I put 50# of zeo sand in an Intex 14″ sand filter and after back washing the pump runs good for a few minutes then the system develops cavitation some how… I cant find any air leaks double checked and re rigged everything twice and the problem still occurs. Im seeing that the recommend supplement for sand amount is 1/2 the weight. Spec is 77# sand so it should be 38.5# zeo. Is it possible that the extra zeo sand is too much for the pump to push through and its blowing pressure back into the pump skimmer and drawing back air from there? It has a pulsing behavior which also makes me thing that is the air source.

    • Darrell, pulsing or surging is usually associated with an air leak, but it could be associated with obstruction after the pump, like (?) too much filter sand. If it is burping air back to the pool, it more likely is an air leak. You mentioned a skimmer… Sometimes skimmers will draw a vortex of air in, maybe disconnect the skimmer and see if the problem still occurs. Also be sure that the o-rings are inside of the suction union connections.

  5. Aaron Hines

    I’m new to owning a pool. We have an approximately 30,000 gallon pool with a DE filter. I accidentally bought Zeosand. Can it be used in the DE filter?

    • Hi Aaron, no it cannot sorry to say. It can only be used in a sand filter. If you don’t want to ship it back ($) for refund, you can probably recoup half your money on Craiglist, Letgo or facebook marketplace.

  6. I have a in-ground vinyl pool can I use ZeoSand or FilterGlass media in my sand filter. The filter use 250lbs sand how much media would I need for the filter?

    • Hi Sam, yes I would say that both zeosand and filterglass are superior to regular sand. We have lots of happy zeosand customers. We stopped selling filterglass some time ago, for a reason unknown to me, but I understand that many sand filter owners prefer it to sand. Generally with both zeo and fg, i think the recommended dose is half of the amount of normal sand, so 125 lbs, however, since they come in 50 lbs bags, go ahead and add 150 lbs.

  7. gerry reagan

    I have a Triton 100 sand filter. If I use Zeosand I apparently need only half as much material as if I use silica sand. This filter should use 600 lbs of silica sand. If I use half as much Zeosand it will fill up less than half of the filter. The freeboard distance should be 11 1/4 inches with silica sand. With Zeosand it will be almost twice as much. Will this affect the filtering or the pressure from the pump?

    • Hi Gerry, great question, thanks! It will lower filter pressure, and raise water flow rate, but should still filter fine with increased freeboard (space above the sand). I tend to want to add more than 50% zeosand, but it need not be all zeosand. If I was you, I would add (regular) pea gravel first, to fill up to the laterals, which is probably about 100 lbs, maybe 130, then add the 300 lbs of zeosand, and maybe an extra bag or two of zeosand (350-400 total), just to be sure.

  8. Christopher

    thinking about changing from paper filter to zeosand will the size pump effect the life of the zeosand? Currently have a 2 hp pentair on a 15000 gallon in ground pool.

    • Hi Christopher, the size pump is very important, but not in regards to the Filter Media, but the Design Flow Rate of the filter itself. All pool filters have a Design Flow Rate, listed in the specs, and on the filter label. If your sand filter has a Design Flow of 50 gpm for example, the pump should be sized to not exceed 50 GPM. How do you know how much flow a pump will produce? You look at the pump flow curve – a chart with Flow Rate on the X axis and Resistance in Feet of Head on the Y axis. How do you know the Resistance for your pool? That’s a bit more complicated, unless you have the original builder specs that displays the ‘system resistance’, expressed as Feet of Head. This sum adds up all the lengths of pipe, all the fittings, and all the equipment, as everything has its own level of resistance. Generally, the average inground pool has around 30-40 feet of head of resistance, but very simple pool systems (no heater, close to the pool, simple plumbing) could have less, and very complicated systems could have more. 2″ piping has less resistance than 1.5″ piping. Anyway… the answer to the question is that when properly sized, the pump will have no effect on the lifespan of the zeosand. And even improperly sized actually too – I don’t expect the life of the sand to be affected either way, but if the pump is too large for the filter, the water will just push right thru the sand, and it won’t filter very well, allowing a lot of small fine debris to slip through unfiltered. Depending on which 2 hp pump you have (different pumps produce vastly different flow amounts) [see the flow chart], it could be too large for a sand filter, depending on the size of the sand filter, or not, if you have a sand filter that has a design flow rate that is below the pumps flow rate capability.

  9. marge kidwell

    I have had a sand filter for 3 yrs and every year its the same thing sand in the pool, laterals have been checked and are ok, will the go thru the laterals and into the pool as easily ? or how about glass?

    • Hi, FilterGlass is larger in size than regular filter sand, and FilterBalls are very large, both would be less likely to pass thru a lateral slit. What you describe is not common however, could be incorrectly sized sand, too much sand in the filter, (coming out after backwashing) or perhaps the pump is too large for the filter size? Filter sand does not normally push thru the laterals.

  10. Purchasing a new filter and am just learning about ZeoSand and FilterGlass. Given that less of either product is needed. Can I purchase a smaller filter size and achieve the same effect or do I need to but the size I would need if I were using sand?

    • Hi Mark, I wouldn’t use a smaller filter size – that could cause you real problems. Buy the largest sand filter you can afford, you can thank me later!

  11. Hubert Shelley

    How long does Zeosand last in comparison to filter sand? Salt system gunnite pool 27000 gal.

  12. which is the best or better, #20 sand, HTH sand, zeosand, any others???? I am betting a san filter for my 15 x 48 Intex pool and have not used sand filters before, please advise. thanks

    • Hi, regular filter sand is #20, .45-.55 mm graded sand labeled “Pool Filter Sand”, like HTH sand. ZeoSand is made with zeolites, and is different from silica quartz, with better micron size filtering ability (10 microns) and also the ability to remove ammonia, a primary component of chloramines, or combined chlorine. It needs to be rejuvenated every few years with a cheap filter cleaner, to reactivate some of it’s properties. FilterGlass is another improvement over sand, with sharper edges that lay flat, and also have longer life and better performance. FilterBalls are the newest filter sand alternative, spun polyester, which our own Ryan Dornan has just installed on his pool, so stay tuned for his (honest) reviews, but so far positive with much clearer water and reduced pump run time. So, basically there are 3 alternatives which all promise better performance than filter sand, which can miss particles below 20 microns in size. However, sand is still the cheapest option, and the only option that you may find locally. So there is that advantage. For such a small pool, you would use a smaller sand filter, maybe the Intex sand filter would be a good fit. You may need some adapters to fit the larger hoses to your smaller wall fittings. you also may need to change the filter sand more often than a larger sand filter, which can go up to 10 yrs in some cases, between sand changes. Aboveground sand filters may need new sand every few years, or even every year in some cases, because the sand bed depth is so small.

  13. Arr there any type of sand filters that can’t use zeosand?

    • Davy Merino

      No mention of that from the manufacturer, and I can’t think of a reason why size would make a difference. Good Stuff, Zeosand…

  14. Michel Hess

    I have a salt water pool. I replaced the sand 5+ years ago and it’s time again. Is glass or zeosand preferred for salt water?

    • Hi Michael, good question. Filterglass and Zeosand are both fine filter sand substitutes that claim to reduce backwashing frequency of length of time needed, which saves water, which saves salt… so maybe a small advantage there. But not really ‘preferred’ for a salt water pool perhaps.

  15. Jason Smith

    Ok im new to sand filter system. My problem is the top of the sand in my tank gets kinda hard and dont let the jet blow water back in pool and the skimmer stops flowing as well.i take the big valve off and break up the sand and im good for about 2 hrs then same thing. What do i need to do. Please help.

    • Davy Merino

      Hi, it could be calcification, from high calcium hardness levels, or other solids (or oils) in the water. I would suggest that you use a sequestering Stain & Scale type of chemical, to keep minerals and metals in solution, and then change the sand, or at least the top 6″ or so of the sand bed. If it continues, dig deeper into the causes. Enzyme treatment may be useful to remove oils, which combine with minerals and dirt, to calcify on the top of the sand bed. If continues without relief, consider FilterGlass or FilterBALLS as an alternative that likely would not clog in such a way.

  16. Can I mix Glass Media & Zeolite together ? (Eg, use 3 layers 1 for course glass, 1 for fine glass and top layer as zeolite ? )

    • Hi, according to Zeolite, you could do this, but they say it’s unnecessary, Zeosand is more effective [than glass]. I could see the two materials mixing however, I don’t think they will stay in perfectly stratified layers, but will mix over time, which may or may not be a problem?

  17. Art Woodring

    I work at a hot springs resort and we’re constantly battling buildup and channeling in our sand filter. It’s likely a result of the minerals in the water, but being that we have a flow-through system we can’t really balance our water.. We’ve tried sand revitalizers and a layer of pea gravel under the sand as well, but still ended up experiencing channeling within a month.. Do you think filter glass might help at all? I’ve also heard that water softener beads might be a possible media replacement, have you heard anything about that? I realize this is an old post, hopefully it’ll still reach you.

    • Hi Art, Channeling can be a result of very high minerals (as found in natural hot springs), but also can be caused or worsened by high water flow, through the sand bed, or low water flow through the sand bed, too. Perhaps installing a filter bypass valve, to reduce flow rates thru the filter, would help. As for Filterglass, it is probably that the glass has properties that won’t allow it to clump and harden. Sand is also a form of glass, so I don’t know for sure. According to this articles: https://www.poolspanews.com/facilities/maintenance/a-glass-act_o – [glass may not clump and harden as readily as sand, due to a weaker bond formed, allowing minerals to backwash out more easily]- Seems Legit! I’d give it a try. Maybe contact the manufacturer directly? ask them what they think?

  18. […] may be interested in a post I wrote about how to improve sand filtration or information about pool filter sand alternatives like ZeoSand or […]

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