The short answer
Use plain silica sand for ballast on a regular lawn, zeolite where dogs urinate, and antimicrobial coated sand where you want urine to rinse through instead of soaking in. Cooling precoated sand is a separate comfort layer. The right pick depends on the job — pet, lawn, or green — not on one "best" infill.
The short version
| Infill | What it actually does | AJ Turf rate | Use it for |
|---|---|---|---|
| Plain silica sand | Ballast and blade support only — holds the turf down and the fibers up; no odor or cooling function | Baseline 1.5–2 lb/sq ft (grade 30/65 for landscape/pet work) | Regular lawns; the ballast layer under an odor-active pet layer |
| ZeoFill (zeolite) | Traps ammonium before bacteria convert it to ammonia gas — odor stopped at the source | 1.5 lb/sq ft (dog ≤45 lb) · 2 lb/sq ft (50–65 lb) · 3–4 lb/sq ft (multiple/large dogs), as the odor layer over ballast | Dog yards, runs, and any pet area that has to not smell |
| Envirofill by Motz (antimicrobial coated sand) | Acrylic-coated rounded quartz sand; urine sits on the coating and rinses through instead of soaking in; antimicrobial protection in the coating | 1.5–2 lb/sq ft | Pet and landscape jobs where rinse-clean, install-and-forget durability is the priority |
| TCool (precoated cooling sand) | Coating stores moisture; the surface cools by evaporation while the infill is hydrated | ½–1 lb/sq ft, as its own layer — never mixed with zeolite | Hot, full-sun landscape and play areas where surface temperature is the complaint |
| HydroChill (Shaw) | Polymer cooling infill; same evaporative principle, hydration-dependent | Experience only — not an orderable AJ Turf spec | Named here because we've used it and it worked; it comes through Shaw's own installation network |
Baseline for regular infill on any job: 1.5–2 lb per square foot. Infill is structural, not cosmetic — at least 1.5 lb/sq ft is what gives the fibers the support to stand up straight.
What does infill actually do?
Infill does four jobs: ballast (its weight holds the turf down), blade support (fibers packed with infill stand instead of folding), cushion, and — only with the specialty products — temperature or odor management. The first two jobs are why every install gets infill, and why the baseline rate is a floor, not a suggestion: an under-filled lawn mats, wrinkles, and shows white spots where sand gathered and dead spots it never reached.
Everything after ballast and support is a choice about which problem you're solving. That is the frame for the whole page: silica solves weight and support. Zeolite solves odor. Coated sand solves rinse-clean hygiene. Cooling sand solves surface temperature, while it's wet. No single product solves all four, and any quote that says otherwise is skipping the trade-offs below.
Plain silica: when is the cheap answer the right answer?
For a regular landscape lawn with no dogs, plain silica sand is the correct, honest spec — washed, rounded quartz sand, brushed in against the grain at the 1.5–2 lb/sq ft baseline. The landscape/pet grade is 30/65 mesh. It drains, it supports the blades, and it costs the least because it does the least beyond those jobs.
Its limit is exact: silica has no odor mechanism. In a pet area it does worse than nothing — it holds urine against the backing, where bacteria convert it to ammonia, and the yard smells by month three. That failure is documented so consistently it has a shape: budget turf, plain silica, sold as "pet turf." Silica's correct place in a dog yard is the ballast layer under an odor-active top layer — not as the pet system itself.
Zeolite: what stops odor at the source?
ZeoFill is a zeolite mineral — 97% pure clinoptilolite — with a negatively charged honeycomb structure. Urine's problem molecule is ammonium, and zeolite traps ammonium before bacteria can convert it into ammonia gas. Every other odor approach works after the ammonia exists; this one works one step earlier, at the source. Its capacity is about 55% of its own weight in urine, and rain and enzyme treatments flush and recharge it — which is why Southwest Florida's frequent rain is a genuine plus for this material.
Because capacity is finite, the rate scales with the dog load, and this is where quotes get honest or don't: 1.5 lb/sq ft for a dog up to 45 lb, 2 lb/sq ft for a 50–65 lb dog, 3–4 lb/sq ft for multiple or large dogs, laid as the odor layer over the silica ballast. A multi-dog quote priced at the landscape rate is under-spec'd on paper before a single bag is opened.
Coated sand: what does the coating buy you?
Envirofill by Motz is a rounded quartz sand with an acrylic coating and antimicrobial protection infused in that coating. The mechanism is different from zeolite's: the coating is non-absorbent, so urine doesn't soak into the grain — it sits on the surface and rinses through, and the antimicrobial keeps the infill itself from becoming a bacteria reservoir. Odor control here is indirect: drainage plus hygiene, not capture. The infill itself carries a 16-year warranty — the benchmark in its class — and our rate is the standard 1.5–2 lb/sq ft.
Under Florida's Rule 62-308.100, AJ Turf's stated reading is that a coated quartz sand remains clean silica sand under section (2)(c), so Envirofill is spec'd freely. (The full rule is taught on our DEP page, linked below.) Pick coated sand when the priority is a lawn that rinses clean and asks little of you; pick zeolite when the priority is killing odor at the source in a heavily used dog area. Heavy-dog households sometimes need the capture mechanism more than the convenience — that's a conversation about your dogs, not about which bag costs more.
Cooling infill: what does it do — and when does it stop?
TCool is a bagged, precoated sand infill whose coating stores moisture; as the sun heats the surface, that moisture evaporates and cools it. We apply it at ½–1 lb/sq ft as its own layer. Two rules are absolute: it cools only while hydrated — on a dry afternoon with no recent rain or hose-down, it is sand — and it is never mixed with zeolite, because the two dilute each other. Cooling is a separate option line, chosen for hot full-sun areas, not a pet-odor answer.
HydroChill (Shaw) is the other cooling infill with a real track record, and we say so from hands-on experience: we have used it and it worked, on the same hydration-dependent principle. It isn't sold as a standalone product — it comes through Shaw's own installation network — so it is an experience mention, never an orderable AJ Turf spec. TCool is the cooling option we spec directly.
What changes for a putting green?
Greens are a different infill conversation: the grade gets finer and the job is ball roll, not odor. The canonical greens grade is 30/50 mesh, with #60 mesh at the fine end for tight, texturized fibers. For the record, our published green numbers are lab-measured only: a stimp of about 8.5 measured at 2.5 lb/sq ft of 60-grit sand, with test conditions stated. We publish what was measured; we don't adopt a target stimp and promise it.
Florida note
Florida heat and humidity accelerate the bacteria that turn urine into ammonia, so the infill decision matters more here than in a dry climate — and Florida rain cuts both ways in your favor: it recharges zeolite and re-wets cooling infill far more reliably than in the arid markets cooling products are usually marketed to. Florida's Rule 62-308.100 also puts infill inside the law now: lawn infill is limited to clean silica sand, rock, shell, or other natural material, with rubber and synthetic infill restricted to playground-equipment footprints. Every product named on this page is spec'd inside AJ Turf's stated reading of that rule.
The honest downside Every specialty infill has a catch its brochure understates. Zeolite's capacity is finite — heavy-use dog areas saturate and need an enzyme recharge or a partial refresh, roughly every 12–24 months in heavy use, and its rate (and cost) climbs hard with dog load. Coated sand costs a premium per bag and its odor control is indirect — it never captures ammonia the way zeolite does. Cooling infill only cools while it's hydrated, full stop. And plain silica, the cheapest line on any quote, is the documented cause of the month-three smell when it's sold as a pet system. There is no zero-maintenance infill for a dog yard.
The gotcha The bait is a single-bag answer: one infill, quoted at one flat landscape rate, for every job on the page. Ask what layer does what. If a pet quote shows only silica sand — or shows a specialty product priced at a landscape rate for a multi-dog yard — the odor layer was never really in the quote. And if a cooling infill is blended into a zeolite layer to save a line item, both products were just diluted into doing neither job.
How AJ Turf handles this
We spec infill by name, by layer, and by rate — in the quote, not discovered on install day. Regular infill runs at the 1.5–2 lb/sq ft baseline. The pet odor layer is ZeoFill at its dog-load rates (1.5 lb/sq ft up to 45 lb; 2 lb at 50–65 lb; 3–4 lb for multiple or large dogs) over the silica ballast. Where an antimicrobial coated sand is the better fit, we spec Envirofill by Motz at 1.5–2 lb/sq ft. The named cooling option is TCool at ½–1 lb/sq ft as its own layer, never mixed with zeolite. Beneath it all, the AJ Method builds the system the infill sits in: a screening-sand base compacted to 95% Standard Proctor (ASTM D698) per Synthetic Turf Council guidance, a woven weed barrier on top of the base, and a perimeter glued to a 3×3×3-inch concrete border with no spikes through the turf. Most installs run $9 to $15 a square foot depending on the turf and the site, with the exact price from a free onsite measurement; installs start at 1,000 sq ft and are typically scheduled within two weeks.
Questions people ask.
Can I just use silica sand everywhere and save the money?
On a lawn with no dogs, yes — that's exactly what silica is for. In a dog area, no: plain silica holds urine against the backing and is the documented route to a yard that smells by month three. Silica belongs in a pet yard only as the ballast layer under an odor-active layer.
What if I have two big dogs?
Then the zeolite rate is the quote, not the landscape rate: ZeoFill at 3–4 lb per square foot for multiple or large dogs, over the ballast layer. Capacity is the math here — the mineral holds about 55% of its weight in urine, so heavy loads need more mineral, and an under-rated quote fails on paper first.
Does cooling infill also fix pet odor?
No. TCool is a comfort product — evaporative cooling while hydrated — and it is never mixed with zeolite, because mixing dilutes both. Odor is handled by the zeolite or coated-sand layer; cooling is a separate layer chosen for hot, sunny areas.
How often does infill need topping up?
Check levels periodically — a stiff-brush feel tells you if the pile is still supported. Zeolite in heavy dog use needs an enzyme recharge or partial refresh on roughly a 12–24 month cycle. If the finished surface shows white spots where sand gathered or dead spots it never reached, the distribution — not just the amount — needs correcting.
Updated 2026-10-13
