# Powdery Mildew Prevention and Treatment UV lighting **URL:** \ **Category:** Troubleshooting\ **Created:** [May 3, 2019, 4:24pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717 "2019-05-03T16:24:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Skydiver](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/skydiver/32/504956_2.png) [@Skydiver](https://ilgmforum.com/u/Skydiver)\ **Post date:** [May 3, 2019, 4:24pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/1 "2019-05-03T16:24:04Z")
I have been reading some articles relating to UV lighting supplements to increase potency and yields and one common thing I’m seeing is the added benefit of preventing and or controlling / killing powdery mildew and other fungus/molds. > **[Home | Cornell Chronicle](https://news.cornell.edu)** > > Cornell Chronicle: Daily news from Cornell University Video of a product offering made just to treat things like PM. Depending how you use it can be used proactively to prevent or after the fact if infested. [![](https://global.discourse-cdn.com/growingmarijuana/original/4X/5/7/1/5710ea807d28b1a401db9a1795ba4e521703e785.jpeg "Clean Light UV for Mold | Powder Mold Remedy | Powdery Mildew Cure Get Rid of PM in Garden") ](https://www.youtube.com/watch?v=kqUUvKLgy28) If you are in an area prone to higher humidity and PM and Botrytis are a concern you may want to look into UV as a non chemical solution to this. My thoughts would be to add good supplemental UV lighting to increase potency/yields during flowering and this is also where plants seem to be more susceptible and the good UV lights will also help prevent this from even getting a foothold. This is definitely something to look into for yourself if you have dealt with or your environment is conducive to this type of disease. I have purchased supplemental 4’ single bulb fixtures (4 of them to cover my 4x8 tent) and will be using them shortly when I flip to 12/12 in about a week. If you want to see the set up and results you can find it here > [@First grow using Worm Poo as medium](https://ilgmforum.com/t/first-grow-using-worm-poo-as-medium/30193): > > Hello all, This journal will chronicle my first and maybe my last attempt lol using worm castings as my main ingredient in the growing medium. I mixed up worm casting 75% and the remaining using equal parts of perlite and granular Diatomaceous Earth and placed the mix in a 1 gallon fabric pot. Once the seed popped I put it into the medium and 4 days later she broke through the Poo. I topped with maybe a 1/4 inch of seed starter mix prior to it sprouting so it had some lighter weight material t… Will be a few days from today 5-3-19 before I post pics of setup. Hope this helps and HAGD ---
**Author:** ![Drinkslinger](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/drinkslinger/32/96644_2.png) [@Drinkslinger](https://ilgmforum.com/u/Drinkslinger)\ **Post date:** [May 3, 2019, 6:54pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/2 "2019-05-03T18:54:35Z")
Interesting. Although, if I read it correctly, the uv is only effective on mold/fungus at night when they shut down their responses. Wouldn’t using uv light at night interfere with photo period plants in flower? @dbrn32 I suppose if it did, one could use it preventatively during veg… ---
**Author:** ![dbrn32](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/dbrn32/32/533801_2.png) [@dbrn32](https://ilgmforum.com/u/dbrn32)\ **Post date:** [May 3, 2019, 7:34pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/3 "2019-05-03T19:34:50Z")
Different kinds of UV light, aren’t they? You would be looking for UVB for plant benefits and UVC to kill molds and bacteria. To best of my knowledge anyway… ---
**Author:** ![Skydiver](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/skydiver/32/504956_2.png) [@Skydiver](https://ilgmforum.com/u/Skydiver)\ **Post date:** [May 3, 2019, 8:42pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/4 "2019-05-03T20:42:52Z")
Just ran across this [https://sanuvox.com/wp-content/uploads/2017/06/FOOD-Marijuana-Powdery-Mildew-Reduction-using-Germicidal-Ultraviolet.pdf](https://sanuvox.com/wp-content/uploads/2017/06/FOOD-Marijuana-Powdery-Mildew-Reduction-using-Germicidal-Ultraviolet.pdf) ---
**Author:** ![Skydiver](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/skydiver/32/504956_2.png) [@Skydiver](https://ilgmforum.com/u/Skydiver)\ **Post date:** [May 3, 2019, 8:59pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/5 "2019-05-03T20:59:45Z")
> **[UVA UVB Lighting To Kill Powdery Mildew And Mold](http://medicalmarijuanagrowing.blogspot.com/2014/07/uva-uvb-lighting-to-kill-powdery-mildew.html)** > > UVA UVB Lighting To Kill Powdery Mildew And Mold I have been doing some research into the use of UVA UVB lighting to either control, kill... ---
**Author:** ![Skydiver](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/skydiver/32/504956_2.png) [@Skydiver](https://ilgmforum.com/u/Skydiver)\ **Post date:** [May 3, 2019, 9:10pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/6 "2019-05-03T21:10:44Z")
> [@Drinkslinger](#): > > Wouldn’t using uv light at night interfere with photo period plants in flower? Not sure but could just have them on for xx minutes before lights on/off and have that total xx minutes overlap into the dark to minimize possible interference. Yea that’s what I got from the first article about when in dark best to expose PM to UVc What I’m gathering from all this is that if no UV A B or C is provided than there is no possible help controlling PM using UV of any type. Several articles suggest that using UV A and UV B in sufficient strength it provides ongoing deterrent to PM where UV C is the terminator to the PM. ![image](https://global.discourse-cdn.com/growingmarijuana/original/3X/c/9/c944d2a4656b5c02c7292bf640169a01f8bd2c61.png) ---
**Author:** ![dbrn32](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/dbrn32/32/533801_2.png) [@dbrn32](https://ilgmforum.com/u/dbrn32)\ **Post date:** [May 5, 2019, 8:00pm UTC](https://ilgmforum.com/t/powdery-mildew-prevention-and-treatment-uv-lighting/30717/7 "2019-05-05T20:00:18Z")
> [@Skydiver](#): > > Several articles suggest that using UV A and UV B in sufficient strength it provides ongoing deterrent to PM where UV C is the terminator to the PM Link 1 suggests about everything I’ve seen is accurate. Link 2 would be more valid if he had linked those studies in my opinion. Also something that people seem to miss. Moving from 25% thc to 26% is considered 4% increase. Those are the increases that studies I’ve seen suggest from supplementing uvb. Not moving from 25% thc to 28-30% thc like some want to believe. That coupled with my personal experience of most people not being able to tell the difference is the reason I’m out of touch with this stuff. Breeder of any strain will list some data about it, we’ll call strain x. Strain x is listed at 20% thc and yields 600 grams per square meter indoor. You have about as much guarantee that you’ll harvest buds at 20% thc as you do pulling 600 grams dry per square meter. Its attainable, but highly unlikely from a grow where everything isn’t 100% on the money. That being said, I’ve yet to meet anyone that could tell me the difference between a couple % thc after smoking both. I’ve also seen everyday users get knocked on their behind from flower well known to be low in thc content. So I have an extremely hard time getting behind this hipster movement for high thc levels. In my opinion, that very movement is destroying most of the good weed available.