I have a sealed room, and I burn sulphur for 4 hours, once a week, during the dark period. Works like a charm to control powdery mildew on strains that get it.
Make sure your room is really sealed--you'll know if it is when you burn the sulfur, any leaks and you will smell it--much more potent than even the dankest herb.
I use it up to 14 days before harvest. Good luck.
if your room is perfectly sealed off nothing else will smell.
except few rooms really are totally sealed.
it's a safer bet to say the whole house will smell.
you brits and your funny spelling!So anyway there is no harm in sulpher vapour what so ever......
in veg and in bloom i burn 6 hours from when the lights shut off.
if you exhaust, the fans need to be turned off.
oscillating/circulating fans need to be turned off.
fill the cup no more than a half inch with sulfur for max efficacy.
burn at least once a week till week 5 of flower.
some report greater efficacy if plants are misted before the burn.
have fun.
The thing about oscillating fans is that they tend to blow in the same pattern. Depending on the size of your room, this can leave areas that won't receive as much sulfur and other areas that will receive more than necessary. As long as you burn for long enough to fill the volume of your room you'll have an even coating all over, which is what you really want. Also, the inner fan motor components don't really like the sulfur coating they get if operating while burning.Oscillating fans need to be turned off? I always read to leave them on to mix up the sulfur within the room. Is this incorrect? If so why?
Also, how much does a half an inch equate to? Half a cup? Quarter cup?
Thanks for the response. Kind of taking my own informal survey on spraying.As far as spraying goes, I got that tip from greyskull and I've tried it periodically but don't notice much of a difference.