The last post was all about mother plants. If you took my advice, your moms' biochemistry is set to produce fast growing, pest-free growth tips ripe for cuttings that root in 5 - 7 days.

This course is about maintaining a sterile system while addressing common mistakes and unknown techniques. Please finish the article, I offer insight that aren't commonly discussed.

Pump housing

The back of most water pumps (where the power cord enters the pump) has a cover plate that shields a small orifice in most water pumps. For most cloning brands this back-plate prevent sterilizers from entering this space effectively.

Permanently remove this plate. On some systems the plate is spot-glued in a couple locations requiring a flat-head screwdriver to pop it off. Once permanently removed, sterilizers can effectively flush this area at each sterilization cycle.
Air-Stones & Air-Lines
Air-pumps, air-lines & air-stones must all be considered when maintaining a sterile system. Boiling your air-stones is the only way to guarantee their sterilization. Air lines can be soaked in your oxidizer of choice at the dosage recommended and times recommended for equipment sterilization at the end of this article. Beware that some brands of air-stones degrade if boiled, so test boil one first. Airlines can be boiled, but tend to harden with time. 
Contamination by Aeration
Air contains dust, debris, bacteria, fungi, and their spores. But aeration improves results in both aeroponic and DWC by boosting oxygen and removing ethylene gas--known to slow rooting and cause senescence in cuttings and plant tissue culture. To achieve the benefits of fresh air without infecting your system, add ¼” - ⅜” AeroBlock filters to your air-lines. With aeroponics you can eliminate the air-stone by securing the airlines in the propagation. Without an airstone, they will injects air directly into the space of the lid, aerating misted water, evacuate ethylene, AND creating positive pressure of HEPA filtered air across gaps and crevices in the systems.
Cloning Collars
Cloning collars are often overlooked when it come to keeping sterile. Attempts to sterilize traditional collars is laborious and unpredictable. Some cloning collars (for example neoprene) do not maintain food grade status with regular exposures to oxidizers.
If you haven’t switched to PermaClone, I recommend replacing collars between cloning cycles for predictable results at every clonal propagation cycle...while maintaining food-grade status. 
Sterilize Cuttings
In all academic publications involving seed germination or plant tissue culture sterilization is the first step. This is a key practice with cuttings. Unrooted cuttings can handle 5 - 10 times the oxidizers compared to rooted plants. This is best done from a pump-sprayer so the oxidizer doesn't get "spent" and each cuttings is exposed to the same effective dose of oxidizer. Below are acceptable mixing instructions for common sterilizers:
  • 25 mL/gal hypochlorous acid (e.g. UC Roots, Clear Rez, Watermax
  • 1 mL/gal Sodium Hypochlorite (e.g. Bleach)
  • 15 mL/gal 30% Hydrogen Peroxide (150 mL/gal of common 3%)
  • 20 mL/gal Peroxyacetic acid (Zerotol, Oxidate 2.0, or Sanidate 5.0)
Touching you System
If you want to remain sterile throughout the cloning cycle, consider what's making contact with the inside of the system. Hold cloning collars the wrong way or putting bare hands inside the lid will contaminate the whole system. Hold cloning collar from the top of the collar only. PermaClone collars are designed tall such that you can grip them from the top. When opening the lid, grip from outside portions of the lid.
Sterilization Between Cycle
Once the adjustments mentioned above are part of your technique, you can deploy a tried-and-true recipe for sterilizing your system between cloning cycles with minimal effort or labor by you or employees.
  1. With PermaClone collars in place, fill the cloner with fresh tap water.
  2. Add 3 - 5 mL/gal Bleach (~ 60 - 100 ppm Free chlorine) & 0.05 - 0.1 mL/gal (1 - 2 drops/gal) concentrated dish soap.
  3. Circulate this mix for 12 - 24 hours, and dump, but do not rinse the system. Lower doses of oxidizer, with longer exposure times are more efficient than high doses for minutes.
  4. Sterilize you PermaClone collars using one of four guaranteed sterilization methods outlined in the PermaClone manual.
  5. Boil air-stones (only if using DWC) and chemical sterilize you air-lines with the same mixed mentioned in step "2.".
  6. After the 12 - 24 hour sterilization, dump the system, do not rinse and with gloved hands, fill the cloner with sterilized collars and start you next cloning cycle when ready.  

Next we discuss The Kaizen of Cloning

In the meantime, feel free to comment below and never be too shy to shoot my an an email to clarify topics or call me out about spelling errors...or more! ;) 


Michael Goldsmith


PS: My articles share knowledge I've accumulated over the years while perfecting my use of PermaClone collars and collaborating with 1000's of customers. My hope is by sharing this knowledge, PermaClone's plant collars will be acknowledged as the best cloning pucks on the market for hydroponic, deep-water culture, and aeroponic systems. Please spread the word! PermaClone has collar sizes to fit the top cloning systems or DIY me to discuss dimension. Thanks for your support! #PermaClone #getsterilegetcloning 

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