1. How do I use Physan 20?

Physan 20 can be used in many different ways:

  • Primarily as a rescue remedy on all Orchids for Crown Rot, Erwinia and Boytritis
  • As an all round Disinfectant to decontaminate pots, floors and workbench areas in the Greenhouse
  • As a sterilizing agent for Greenhouse tools and equipment
  • As maintenance spray to combat and control Fungal diseases on flowers and plants
  • Clean out closed hydroponic Irrigation systems
  • Controls Algae on walkways, paths and hard garden surfaces
  • Excellent for de-flasking and soil drenching
  • Excellent for controlling algae in fountains, birdbaths, swimming pools and decorative water displays

Download Full Physan 20 Imperial Measurements Product Booklet here:

Download Full Physan 20 Metric Measurements Product Booklet here:

2. What plants can I use Physan 20 on?

Physan 20 can be used on all sorts of plants! Below is a chart showing some of the plants and diseases that are treatable with Physan 20. The Green dots indicate that Physan 20 is effective. Download Usage Guide PDF here:

Download Full Physan 20 Imperial Measurements Product Booklet here:

Download Full Physan 20 Metric Measurements Product Booklet here:

3. Do I need to wear any protection when using Physan 20?

It is recommended you use protection when handling Physan 20 in its concentrated form, however, when Physan 20 is diluted with water, it is completely safe to use, gloves and safety equipment are not required.

The diluted Physan 20 solution is safe enough to dip ones hands in. It is not a primary eye or skin irritant, and if splashed on clothes will not harm them. The solution is pleasant smelling and requires no special ventilation to use.

4. Is Physan 20 Toxic for my dog?

In it's concentrated form, Yes, however once diluted it is safe for all birds and mammals. Physan 20 is only toxic to fish, as it clogs up their gills and impedes breathing, so do not use it on your water feature if there are fish swimming around. Physan 20 is also Bee Friendly, so no need to worry about harming your local insects, birds and mammals.

5. Is it safe to clean my pool and House with Physan 20 if I have children around?

Absolutely, when diluted with water Physan 20 is safe to use around all children and pets - EXCEPT FISH.

6. Is Physan 20 environmentally Friendly?

Yes it certainly is. Physan 20 is one of the few disinfectant products which is EPA approved and bio-degradable. 

7. How long does Physan 20 last for?

When left in the bottle in its concentrated form Physan 20 can last up to 10 - 15 years.

When diluted it can last up to a week - a simple way to check if the solution is still active is to give it a little shake, if you see slight soap bubbles this indicate the solution is still active and can be used. 

Physan 20 has residual germicidal activity, which means it remains effective for a period of time, particularly on hard surfaces. The solution itself remains active and can be used over time. In addition, a 10 minute contact time is all that is required to disinfect.

Physan 20 is a naturally long lasting contact fungicide. Physan 20 leaves a bacterio-static barrier and serves as an excellent wetting agent, performing and lasting much longer than other Fungicides on the market today.

8. What are the benefits of using Physan 20?

  • Broad spectrum disinfectant with a huge variety of plant and surface applications
  • Environmentally friendly and biodegradable - EPA approved for direct use on plants
  • Gloves not required for use with diluted solution and is safe for use around children, mammals and plants.
  • Highly stable product with a Long shelf life that retains antiseptic and germicidal properties for years compared to hydrogen peroxide, chlorine bleach, and alcohol
  • Available in a cost effective concentrate meaning a little goes a long way
  • Non-flammable
  • Excellent wetting agent - Long lasting
  • Pleasant odor and does not discolor skin
  • No need for respiratory gear, jump suits or specialised safety equipment.
  • It stands alone on the NZ market as there is no product remotely like it

9. Should I disinfect my tools with Physan 20?

Absolutely, Physan 20 is particularly useful when it comes to disinfecting cutting tools in the green house. Simply mix a solution up in a vessel, dip your tool in, give it a few swings and Presto! Your tool is officially sterilized. You can also use Physan 20 to disinfect your work areas, benches, pots, flats and flower buckets. Dilution rates for these applications are as follows:




Disinfect Cutting Tools 4 teaspoons Physan20 per gallon water
Mold/Mildew Control on Surfaces 1 1/2 Tablespoons Physan20 per gallon water
Disinfect Work Areas and Benches 1 Tablespoon Physan20 per gallon water
Disinfect Pots/Flats/Flower Buckets 1 Tablespoon Physan20 per gallon water

10. How does Physan 20 work?

Physan 20 disrupts the cell membrane of the Pathogen to destroy and/or disable it from affecting the plant. It has an inherently high wetting and penetrating action that provides a deep and intimate contact between the antiseptic-germicide and any microorganisms, dirt e.t.c. When used an almost unseen residual anti-bacterial film is left on the surface, this film prevents and inhibits the growth of micro organisms over a period of several days. Download Technical Data PDF here:

11. Does water temperature affect Physan 20's effectiveness?

Physan 20 is effective in either hot or cold water, however it's effectiveness increases with a higher water temperature.

12. Will Physan 20 change the PH level of my soil?

Physan 20 is PH neutral and will not effect the pH of any potting mix/dirt, Period. The PH ratings of Physan 20's aqueous solutions fall within the range of 6.5 to 7.5. Physan 20 is cationic in its reaction to surfaces throughout the entire PH range and maintains its bactericidal effect throughout the whole PH range.

13. Is Physan 20 compatible with other sprays and can it be mixed with other chemicals?

Physan 20 can be mixed with some chemicals without problems as it is typically a soap compound so It won’t cause any harm. However, take note that if mixed with another product, it may impede Physan 20 from contacting the surface your cleaning, thereby compromising its disinfecting abilities. Check page 3 of the Technical Data PDF for more info.

14. Can Physan 20 be used on Vegetables or fruit bearing plants?

Yes, Physan 20 can be used on Vegetable and fruit plants. Just treat the disease as you would any other plant. However it's important to note - DO NOT CONSUME IMMEDIATELY AFTER SPRAYING - The down time for consuming after spraying should be at least 4 - 5 days ; 1 week is ideal. 

15. Can Physan 20 be used with / around metal machinery or plastic e.t.c.?

In it's original concentrated form - NO - it is never recommended to use the concentrated matter undiluted on anything - EVER. Physan 20 must always be mixed with water no matter what the use or application is. Once Physan 20 is mixed and diluted with water to the correct dilution as specified in the handbook, it is non-corrosive to all metals in normally used applications for swabbing, irrigation cleaning, mopping and rinsing. It will also not damage or mar natural rubber, glass and painted or plastic surfaces. Download Technical Data PDF here:

16. Is physan 20 a hazardous chemical?

Yes, Physan 20 is classified as a class 8 Dangerous good according to NZ MPI regulations. You can download the entire Safety Data Sheet Here for all the information you need.

17. Why is Physan 20 so bloody expensive to ship / deliver?

Because Physan 20 is classified as a class 8 Dangerous good, it can't be handled by your average post office or courier company. Therefore we need to use a specialised dangerous goods delivery company - We use ChemCouriers and they are the cheapest alternative we have been able to find in New Zealand by a long shot.

It is also important for us to state that we are not making a profit or marking up any of the delivery charges. What you are seeing is the true Delivery cost.

For more info on delivery just visit out Delivery Info Page