ZeroTol® HC

Broad Spectrum Algaecide / Bactericide / Fungicide

ZeroTol HC is a broad-spectrum algaecide, bactericide and fungicide peroxyacetic formulated for the homeowner and hobby grower. Protecting plants from diseases has never been easier; ZeroTol HC provides an effective solution for homeowners and gardeners wanting healthier plants and lawns.

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Active Ingredients

  • Peracetic acid


  • OMRI Listed
  • Fungicide, bactericide, and algaecide
  • Can be used on all stage of plant growth
  • Kills plant diseases on contact
  • Promotes stronger roots and stems
Tomatoes ripening on the vine

Protecting plants from diseases has never been easier!

ZeroTol HC provides an effective solution for homeowners and gardeners wanting healthier plants and lawns. This OMRI-Listed product adds convenience to organic gardening; the clean chemistry of ZeroTol HC disinfects plants AND tools to help stop the spread of disease from plot to plot. Following the weekly treatment plan with ZeroTol HC helps develop healthy, flourishing, and disease-free flowers, lawns, and produce.

  • Usage
    • Usage
    • Turf
    • Lawns
    • Hydroponics
    • Aquaponics
    • Gardens
    • Landscape beds
    • Surface Treatment
      • Pots
      • Trays
      • Cutting tools
      • Equipment
      • Walkways
      • Floors
      • Walls
      • Watering systems
    • Treatment for plants
      • Flowers
      • Ornamentals
      • House plants
      • Vegetables
      • Berries
      • Fruits
      • Trees
      • Shrubs
  • Directions

    Plant treatment


    1. Use a dilution 0.85 fl. oz. (5.1 teaspoons) of ZeroTol HC per gallon of water. Do not reuse already mixed solution, make fresh daily.
    2. Spray, mist or fog plants in early morning or late evening.
    3. Thoroughly wet all surfaces of plant, upper and lower foliage, including stems, branches and stalks to ensure full contact with plant and flower tissue.
    4. Apply consecutive applications until control is achieved and then follow directions for preventative treatment.


    1. Use a dilution 0.64 fl. oz. of ZeroTol HC per gallon of clean water.
    2. Spray, mist, or fog plants.
    3. Thoroughly wet all surfaces of plant, upper and lower foliage, including stems, branches, and stalks.
    4. Spray every 5-7 days as a preventive treatment.

    Note: If disease recurs, return to corrective measures for 3 days.

    Surface treatment

    1. Sweep and remove all debris. Use power sprayer to wash all surfaces to remove loose dirt.
    2. Use a dilution 0.85 fl. oz. (5.1 teaspoons) of ZeroTol HC per gallon of water.
    3. Apply solution with mop, sponge, pump or power sprayer, or fogger to thoroughly wet all surfaces.
    4. Allow to remain wet with solution for one (1) minute. Air dry. Do not rinse.
    5. Scrub off heavy growths of algae and fungi following application. Use a solution of ZeroTol HC to wash away dead growth.


Botanical Fungicide, Bactericide
Powered by HOLDit® Technology

Guarda® is the first EPA-registered, bactericide/fungicide with botanical thyme oil as the active ngredient. Take advantage of up to 14 days of residual activity and say Cu-later to heavy metals.

Active Ingredients

  • Thyme oil
Strawberries growing in hay
Large soybean field growing in rows
  • No use restrictions
  • MRL/tolerance exempt
  • Extended performance up to 14 days
  • Low risk of resistance: ideal for IPM programs
  • 0-hour REI; zero-day PHI
  • Tank-mix compatible with most agrichemicals
White budding flowers on an apple tree

Mode of Action

Guarda combats plant pathogens and provides continued defense through cellular damage and inhibition of these organisms. It is the first EPA-registered crop protection tool with thyme oil as the registered active ingredient, and it is formulated like no other, as the thyme oil is standardized by its active content, thymol. Guarda’s mode of action is cell wall destruction, telomerase inhibition, and cell membrane damage leading to loss of cytoplasmic content and ergosterol depletion.

The HOLDit® Advantage

The HOLDit Technology in Guarda captures the active ingredient, thyme oil, and allows it to remain active over a period of time extending performance against plant pathogenic organisms.

Without HOLDit, thyme oil is rendered inefficient because the active ingredient thymol volatilizes in the environment, never allowing for correct contact time to destroy microorganisms. This plant-based inert is tolerance exempt and approved for use without restrictions.

ZeroTol® HC

Broad Spectrum Algaecide / Bactericide / Fungicide

ZeroTol HC is a broad-spectrum algaecide, bactericide and fungicide peroxyacetic formulated for the homeowner and hobby grower. It is a no residue sustainable chemistry that is proven to keep diseases such as Powdery Mildew, Botrytis and Pythium at bay. With no toxic residues and a 0-day preharvest interval, ZeroTol HC gives homeowners peace of mind as it is safe for people, pets and wildlife.

Active Ingredients

  • Peracetic acid


  • OMRI Listed

ZeroTol HC’s specialized chemical composition partners well with conventional and biological pest management practices already in use. As a no residue disinfectant, it can be followed by biological applications that protect plants through colonization.

  • Promotes stronger roots and stems
  • No residues
  • Kills disease on contact
  • Environmentally responsible — Sustainable chemistry
  • Can be used around people, animals, pets, birds and other wildlife
  • 0-day preharvest interval
Tomatoes ripening on the vine

Where can ZeroTol HC be used?

Greenhouse and Ornamentals

Home, hobby and small hydroponic growers can use ZeroTol HC to control diseases on ornamentals in the landscape, houseplants, vegetables, berries, herbs and other edible plants. Zerotol HC can be used to disinfect greenhouse surfaces and equipment, such as: glazing, plastic, pots, flats, trays, cutting tools, benches, work areas, walkways, floors, walls, fan blades, watering systems, coolers, storage rooms, structures and equipment.

Hydroponics and Aquaponics

Treat hydroponic and aquaponic growing systems to control water-borne pathogens such as pythium and fusarium.

Turf and Landscape

Treat turf in well-established lawns for disease and algae. Control landscape, tree and shrub diseases such as powdery mildew.

  • Greenhouse and Ornamentals Pathogens
    • Downy Mildew
    • Powdery Mildew
    • Leaf Blight
    • Anthracnose
    • Botrytis*
    • Xanthomonas*
    • Rhizoctonia*
    • Leaf Spot*
    • Pseudomonas*
    • *Not approved for use in California.
  • Turf and Landscape Pathogens
    • Anthracnose
    • Brown Spot
    • Dollar Spot
    • Summer patch
    • Copper Spot*
    • Strip Smut*
    • Take-All Patch*
    • Leaf Spot*
    • Fusarium*
    • Fairy Ring*
    • Pink Snow Mold*
    • Pythium*
    • Phytophthora*
    • Rhizoctonia*
    • *Not approved for use in California.
  • How to use ZeroTol HC
    ZeroTol HC Application Rates
    Foliar Spray 25 mL/gallon Apply at 5-7 day intervals. Spray for contact of entire shoot, leaves and stems down to media. Use 2 gallons of solution per 400 sq. ft.
    Hydroponics and Aquaponic 10 mL/50 gallons Use higher label rate for established algae. Apply 1-time weekly.
    Surface Treatment 25 mL/gallon Allow to remain wet with solution for 1 minute.

ZeroTol® 2.0

Broad Spectrum Algaecide / Bactericide / Fungicide

ZeroTol 2.0 works on contact to kill plant pathogens and their propagules, including spores. Formulated with our powerful and stable peroxyacetic acid chemistry, use ZeroTol 2.0 starting at propagation through production to protect crops, including fruits and vegetables.

Active Ingredients

  • Hydrogen Peroxide
  • Peracetic acid


  • OMRI Listed
  • Section 2 (ee) Recommendation Bulletin

ZeroTol 2.0 is the fire extinguisher for bacterial, fungal, or algal fires, it immediately knocks out harmful organisms that could damage turf, crops and ornamentals. ZeroTol 2.0’s fast-acting oxidation process has broad-spectrum application. By incorporating ZeroTol 2.0 into an integrated pest program, and using it before pathogen emergence, it creates a more prepared growing operation.

ZeroTol 2.0 controls the following pathogens

  • Algae
  • Alternaria
  • Anthracnose
  • Aphanomyces
  • Bacterial spots and rots
  • Botrytis (grey mold)
  • Downy Mildew
  • Erwinia, Fusarium (root rot)
  • Leaf Spot
  • Phytophthora (blights, rots)
  • Plasmopara
  • Powdery Mildew
  • Pseudomonas
  • Pythium
  • Rhizoctonia
  • Rust
  • Scab
  • Smut
  • Thielaviopsis
  • Uncinula (powdery mildew)
  • Xanthomonas
  • Wilts & Blights
  • Ralstonia solanacearum (brown rot, bacterial wilt)
  • Sclerotinia sclerotiorum (white mold)
  • Tobacco mosaic
  • How to use ZeroTol 2.0
    ZeroTol 2.0 Application Rates
    Foliar spray 0.5–1.25 fl. oz./gallon. Use non-ionic spreader/sticker. Use lower rate more frequently on softer vegetation.
    Spray Intervals: 5–7 days
    Drench 0.5–1.25 fl. oz./gallon. Use non-ionic wetting agent.
    Spray Intervals: As needed to remove root zone infestation
    Mist propagation – continuous rate 25.6 fl. oz.–128 fl. oz./1,000 gallons
    Cutting dip 0.5 fl. oz./gallon. 45–60 seconds, air dry
    Turf 1.25–2.5 fl. oz./1,000 sq. ft. 2–3 gallon solution. Use non-ionic wetting agent to aid penetration and contact.
    Boom irrigation When using boom irrigation inject ZeroTol 2.0 as a continuous application at a rate of 1:2,500-1:5,000.
    Fogging ZeroTol 2.0 can be applied as an aerosol/fog using approved commercial cold or thermo fogging equipment. Use a rate of 5.0-16.0 fl. oz. of ZeroTol 2.0 per 10,000 sq. ft of greenhouse area mixed in 0.5-1.0 gallon of water.
    * Not approved for use in California
    Pre-plant dip Use 64 fl. oz. per 50 gallons of water, a dilution of 1:100. 2. Immerse plants or cuttings. Remove and allow to drain. Do not rinse.
    Nutrient/Reservoir tank Use at a rate of 1:2,000-1:10,000 (0.128-0.64 fl. oz per 10 gallons of water). Use lower rates (1:5,000 or less) for seedlings and/or plants with sensitive root systems. Recharge as needed when fresh water is added, or at least once every 5-7 days.
  • ZeroTol 2.0 tank mix and spray instructions

    Conventional Fungicides

    Active Ingredient Product Name (Examples) Compatibility
    Azoxystrobin Heritage, Mural*
    Boscalid Pageant Intrinsic*
    Captan Captan
    Chlorothalonil Clevis*, ConSyst*, Concert II*, Daconil Ultrex, Daconil, Weatherstik, Echo, Exotherm Termil, Manicure 6F
    Copper Hydroxide CuPRO 5000, Kalmor
    Cyazofamid Segway
    Fenhexamid Decree
    Fenamidone Fenstop
    Fluaxastrobin Disarm
    Fludioxonil Medallion
    Flutalonil Prostar
    Fluopicolide Adorn
    Fosetyl-aluminum Aliette
    Iprodione Chipco 26019, Lesco 18 Plus, OHP 26GT-O, 26/36*
    Mancozeb Clevis*, Dithane, Fore, Junction WSP, Pentathlon, Protect, Zyban*
    Mefenoxam Subdue MAXX
    Metconazole Tourney
    Myclobutanil Clevis*, Eagle, MANhandle*, Systhane
    Propiconazole Banner MAXX, Concert II*
    Phosphorus Acid OxiPhos, Alude
    Tebuconazole Torque
    Thiophanate-methyl AllBan Flo, Banrot*, 3336, ConSyst*, OHP 6672, Spectro 90*, SysTec 1998, T-Storm, TM 4.5, TM/C*, 26/36*,
    Triflumizole TerraGuard SC
    Triticonazole Trinity
    Trifloxystrobin Compass

    Conventional Insecticides/Miticides

    Active Ingredient Product Name (Examples) Compatibility
    Abamectin Avid
    Acephate Orthene/1300 Orthene TR/ Precise
    Acetamiprid TriStar
    Bifenthrin Attain TR/Talstar
    Chlorpyrifos DuraGuard ME
    Cyromazine Citation
    Diflubenzuron Adept
    Flonicamid Aria
    Imidacloprid Marathon/Benefit/Mantra
    Spinetoram XXpire
    Thiamethuxam Flagship

    Organic/Biorational/Botanical Bactericides/Fungicides/Insecticides/Miticides

    Active Ingredient Product Name (Examples) Compatibility
    Azadirachtin AzaGuard, Azatin O, Azatin XL
    Clarified Hydrophobic Extract of Neem Oil Triact 70
    Copper Octonoate Camelot O
    Mineral oil Ultra-Pure Oil/SuffOil-X
    Potassium salts of fatty acids M-Pede
    Pyrethrins Pyrethrum, Azera, Pyganic EC
    Spinosad Conserve
    Sulfur Microthiol Disperss
    Sodium Percarbonate PerCarb, TerraCytePRO


    Active Ingredient Product Name (Examples) Compatibility
    Beauveria bassiana BioCeres WP, BotaniGard
    Isaria fumosorosea Ancora
    Metarhizium anisopliae Met52
    Gliocladium catenulatum PVent, PreStop
    Streptomyces lydicus Actinovate
    Streptomyces griseovirdis MycoStop
    Bacillus subtilis (various strains) Cease, Rhapsody, Companion
    Bacillus amyloliquefaciens (various strains) Double-Nickel, Triathlon
    Coniothyrium minitans Contans
    Trichoderma harzianum Root-Shield
    Trichoderma virens SoilGard


    Active Ingredient Product Name (Examples) Compatibility
    Alkyl phenol ethoxylate/Alcohol ethoxylate Activator 90
    Yucca Extract (Saponin) Yucca Agaide, ThermX-70

    * Compatibility at 1.0% v/v (1:100) strength ZeroTol 2.0 solution. It’s recommended to add ZeroTol 2.0 first to full volume of water in tank, mix and then add the tank mix partner.

    ZeroTol 2.0 solution is tank mix compatible with listed solution. Due to varied sensitivity of plants to chemicals under given set of growing conditions and plant varieties, it’s recommended to conduct an additional phytotoxicity evaluation on small set of plants to ensure tank mix solution is safe before using on large scale.

    ZeroTol 2.0 solution is either not tank mix compatible or tank mix partner is not specifically tested for compatibility. Standard jar test and phytotoxicity evaluations need to be conducted before considering for tank mixing.