How to sterilize coco

Instruction on decontaminating coco medium by chemical sterilization or heat sterilization.

Materials Needed(dependent on preferred method):

Personal protective equipment (PPE):

• Gloves

• Safety goggles

• Lab coat or apron

Safety Precautions:

• All laboratory safety protocols should be followed while sterilizing coco.

• Gloves and safety goggles should be worn to prevent contact with bleach and other chemicals.

• Ensure proper ventilation.

• Do not mix bleach with other chemicals, especially ammonia-based ones or alcohol, as it can produce harmful gases.

Procedure for sterilizing coco medium with chemicals:

1. Bleach:

    

   1. Submerge coco in a mixture of 1 part bleach to 19 parts water (5% solution) for 30 minutes. This is ~4 teaspoons of concentrated bleach in every gallon of water. Stir the coco around to make sure all of it gets exposed to the bleach. Then rinse with water until you can no longer smell bleach.

2. Hydrogen peroxide:

    

   1. Similar to the bleach method, you can soak coco in a hydrogen peroxide and water mixture.  Submerge coco in a mixture of 1 part 35% hydrogen peroxide to 499 parts water (2 mL hydrogen peroxide per liter of water) for at least 4 hours. Some references recommend 24 hours. Then rinse thoroughly. Note - this process will not destroy viroids, but is very effective at killing fungal pathogens. 

3. Quaternary ammonium salts (aka products like KleenGrow or the like):

   1. You can soak coco in a 1% solution (1 part Quat to 99 parts water) for 30 minutes stirring occasionally to ensure all the growing substrate is exposed, then rinse thoroughly. Note - this process will not destroy viroids, but is very effective at killing fungal pathogens.

Procedure for sterilizing coco medium with heat:

1. Heat

   1. Heat sterilization can be very effective at destroying pathogens and does not introduce chemicals into the growing media. However, this type of sterilization does require an oven or steam generator large enough to be practical for sterilization if bulk quantities are needed. 

      
      To heat sterilize coco, steam or heat the coco at 800C, or roughly 1800F for 30 minutes.  Note - this process will not destroy viroids, but is very effective at killing fungal pathogens.