4 Replies Latest reply on Nov 10, 2016 12:16 PM by jillm

    What is this white stuff on rockwool?




      I see this frequently and finally decided to ask what it is and how I should handle it. My rockwool has a tendency to grow white stuff on the tops of it. Here's a pic of a brand new seedling I put in my indoor tower a few days ago. I have the water set to run 15 mins on, 45 mins off and I have 2 small fans running, one on each side of the tower.


      Thank you!




        • Re: What is this white stuff on rockwool?

          Hi jillm, That appears to be mold. As you may already know, mold is a fungus that likes high humidity, stagnant air, darkness and warm temperatures. Since you already are using the recommended stock nutrient pump timer settings for an indoor TG (15m-On, 30-45m-Off) and have employed fans to increase air circulation, I would look at your ambient air humidity and nutrient solution temperature. Lowering air humidity levels below 50% and keeping the nutrient solution (and ambient air) temperatures at the low end of the optimal 65 - 75° F. range will help mitigate mold growth. Also, because of the way mold / fungi propagate, once you have it, it's not so easy to eliminate. Some growers use hydrogen peroxide (H2O2) spray to kill mold however, I tend to not recommend this course of action because there are too many ways to use H2O2 and get it wrong (to the point it may be a safety and/or health issue). Another way to mitigate mold is to sanitize your growing system and tools. When it comes time to perform your total tower cleaning, I highly recommend that you consider performing the "SANITIZING the TG" steps of the following procedure:


          How to Clean the Tower Garden



          -- [please mark this post as "Correct Answer" (under Actions menu) and/or "Helpful" when appropriate] -- Happy Growing! -JoeD towergarden level2concepts tgtech TG Tech

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