This sounds interesting - how does this work??
Sulfur is an element that is naturally in a solid state. When you heat it up it melts and burns off in extremely small particles which are now floating around in your grow area. When you do your burns you want to have really high RH in your grow area so in tents you will want be running a humidifier. The high RH in conjunction with the extremely small air-born particles cause the particles to stick to the surface of the leaves and stems. This lowers the pH of the leaf surface to an uninhabitable environment for pests and mold spores. No PM, no spider mites and it will even knock out the dreaded hemp russet mites.
You will have to do several burns, spaced out about 3-4 days apart to knock everything out depending on your infestation level. And its not as effective at treating PM as it is at preventing PM if that makes sense. But the plants absolutely love the burns and to me its insane not to do them regardless if I am seeing anything or if I am completely clean and pest free. Doing them ensures that even if one or two nasties snuck in the tent, there isn't going to be an issue in the future. They simply can't live on your plants if you are doing the burns.
When you do the burns, turn off all exhaust fans, and put any air flow fans on their lowest setting. You want the air moving lightly throughout the tent. Remember all those particles that are floating and coating? Without that air flow to get them moving and circulating throughout the tent, it won't be an effective burn. So exhaust fans off, and turn down your air flow fans in the tent. Now the most important (as was warned to me, but I haven't tested to determine if it was valid or not), remove your lights from the tent or cover them in something waterproof. As was told to me, the ultra high RH and the sulfur particles will corrode the electric system of your lights. Cool....easy enough. Is it pain to take down my lights? Yes it is. But my lights are not cheap and I ain't rich so I am not testing the theory of leaving your lights in will corrode your lights and ruin them very quickly. It ain't that big of a deal to remove my lights, do the burns, and then put the lights back up. That way I guarantee that it won't hurt my lights.
Besides I used to spend up to 10 hours a week spraying plants when I was battling pests and or PM, so not having to do sprays and only having to move a few plants to take down my lights and put them back up (takes me 10 min max per tent per burn) is a cake walk!! Sign me up please! The sulfur doesn't even smell that bad. If you are using 99% pure elemental sulfur prills there isn't much smell and its gone in a few hours after the burn is done. 100% pure sulfur is actually odorless.....so the less pure sulfur you burn, the more its going to stink. I think that the people that bitch about the smell are burning less pure sulfur.
I run my burner on its own timer.....so I don't have to fuss with the light's timer to do the burns. When the burns are done, I give it an hour or two minimum before I turn on my exhaust fans. Once I do that, I let them run for a bit before I even think of putting my lights back in. Basically, don't go throwing your lights back into a tent full of sulfur particles and 99% RH unless you want to test the above theory about it ruining your lights.
I think that about covers it. Any other questions on this, please feel free to ask. I'm all about the burn!!