Dog turf infill: what zeolite, coated sand and silica sand do with urine

01What does each infill do with dog urine?

The smell is ammonia. Motz, the maker of Envirofill coated sand, puts it plainly: urine residue “will slowly release ammonia back into the air” as bacteria break it down (Motz). Each infill meets that ammonia at a different point.

The wider range of infills, including organic and cooling products, is in our guide to artificial turf infill types.

02How does zeolite hold the smell, and what lets it go?

Zeolite for turf is the same kind of mineral sold for pet litter and odor control. The U.S. Geological Survey counts odor control as the second-largest domestic use of natural zeolite, 15% of sales tonnage in 2025, and names artificial turf infill among its newer markets (USGS).

Its crystal framework carries a negative charge, so it pulls in positively charged ammonium from urine. ZeoFill, which sells zeolite infill under the OdorZorb name, says this “prevents ammonia from forming into a gas” (ZeoFill FAQ). A granule holds only so much, though, and something has to empty it:

• ZeoFill says rain does it. Sodium in rainwater releases the granule and the zeolite “will naturally recharge when it dries again.” The same page says watering with household tap water “will be ineffective,” and suggests an enzyme cleaner through dry spells.
• Water treatment plants use salt. When clinoptilolite’s ammonium capacity is used up, it is regenerated with sodium chloride or other sodium solutions, a University of Stuttgart study notes (Molecules). That is a treatment-plant process, not a yard chore.
• Northern Colorado is short on rain. The Greeley UNC station, the nearest NOAA station to Greeley, Johnstown and Milliken, averages 14.65 inches of precipitation a year (1991–2020 normals).

So treat zeolite as a buffer that stretches the time between cleanings, not a replacement for them.

03Is coated sand better than plain silica sand with dogs?

Only if the coating carries an antimicrobial. Acrylic-coated sand is silica sand sealed in a colored coating; the odor control comes from what is in that coating.

• The antimicrobial claim. Envirofill carries Microban in its coating. Motz says it cuts ammonia odor from urine “by up to 99%” by disrupting the bacterial process that turns urine into ammonia, and that the coating keeps porous sand grains “from harboring and growing bacteria from the inside.” Microban says its protection “never washes off or wears away” (Microban).
• The case against plain sand. Motz says raw sand “can actually make urine smells worse” because it traps urine and slows drainage. Synthetic Grass Warehouse, a turf distributor, adds that most silica sand is fractured and angular and compacts under heavy rain and foot traffic (SGW). Both sell coated sand, so weigh that.
• What the bag won’t tell you. “Coated” and “antimicrobial” are different words. Ask for the spec sheet and look for the antimicrobial named on it.

Plain silica still works as ballast, and SGW lists it next to coated sand as the weight over a zeolite layer. It just carries no odor treatment.

04How much of each goes down in a dog yard?

Zeolite can’t be the whole fill. SGW says it is “not heavy enough to be used as a primary infill.” Wet, it absorbs up to 81% of its weight in water and 55% of its weight in urine; once dry, it cannot keep the turf ballasted, “which may allow wrinkles in the turf.” That is why dog yards layer it under sand.

SGW also puts about a quarter inch of zeolite on the compacted base before the turf goes down, and finishes the infill about half an inch below the blade tips. The turf’s own spec sheet still sets the depth. In Firestone, where the code requires a pile of 1.75 to 3 inches, check the maker’s figures for that height rather than for short pet turf.

Motz advises checking depth once a year, or every six months in heavy-use areas; our guide to adding infill covers top-ups.

05What does Firestone’s code allow under a dog yard?

Firestone’s development code spells out what goes in the turf: infill “shall be a non-toxic anti-microbial material such as silica sand or acrylic coated sand to prevent odors and bacteria formation,” and “Crumb rubber filler shall be prohibited” (Firestone Development Code 16.6.4). The same section lists odors among the kinds of deterioration a turf area may not have, next to stains, holes and seam separations. A permit comes first, with no fee for single-family homes.

Zeolite isn’t named. “Such as” leaves room, but whether a zeolite layer under the sand meets the rule is Firestone’s call. It depends on how the town applies that wording; ask Firestone Planning before the permit goes in. Not legal advice. Other towns’ turf rules are in our guide to artificial turf rules in Northern Colorado.

06Will rinsing the infill run into watering rules?

Whatever the infill, dog turf needs rinsing. Motz advises rinsing at least once a month, and as often as weekly where little rain falls and big dogs share a small yard (Motz). Two towns’ 2026 rules show how that can collide:

• Milliken bars sprinkler irrigation with town water from 9 a.m. to 7 p.m. and all day Sunday, but allows hand-watering with a shutoff nozzle any day, outside the lawn-sprinkling limits (Town of Milliken).
• Johnstown is on a Level 3 schedule through October 15: two assigned days a week and no watering from 10 a.m. to 6 p.m. Its Level 3 guidance says hardscapes should be swept rather than spray-washed, and hand watering belongs on your watering day with an automatic shutoff nozzle (Town of Johnstown). Turf isn’t mentioned. It depends on how the town reads it; ask the Town of Johnstown before rinsing off your assigned day.

Our guide to watering artificial turf covers the other towns.

07What should I ask an installer about infill for dogs?

• Which infill, by product name, and how many pounds per square foot of each layer? A good answer names products and gives numbers that match the maker’s sheet for your turf’s pile height.
• Is there an antimicrobial in the sand, and which one? A good answer names it and shows it on the spec sheet, not just “coated.”
• Where does the zeolite go? A good answer puts it low: on the base, in the first lift, or both, with sand on top for weight.
• How is it brushed in? In lifts, and dry: ZeoFill says wet zeolite clumps and won’t drop into the thatch.
• In Firestone, is the infill written into the permit?
• What rinsing and top-up routine do you suggest for my dogs?

What changes between pet turf and ordinary turf beyond the infill is in our guide to pet turf and regular turf, and our pet turf page covers dog yards from the ground up.