I'm all for
prevention. Better safe than sorry! Those spots could be spider mites, or poop from caterpillars or worms. The white spots also. I had some problems on my current grow and decided to use neem oil to get rid of it. It also keeps them away, because it stays on the leaves of the plant for a long time. It's supposed to kill all kinds of harmful insects by messing with their reproductive organs. It might even kill some types of fungus. It seems to have done the trick with my plants.
Neem oil recipe
You need to make a mixture of neem oil and water. This obviously won't mix. You need to add an emulsifier. I use soft soap. Here's the recipe:
First add the soap to the water and mix, then add neem oil and shake vigorously. If there's still oil floating on the water, add some soap. To one liter of lukewarm water add 2ml-4ml of neem oil and half the amount of soft soap.
Edit: you'll need cold pressed neem oil.
Use within an hour after making the mixture.
How to use it
Use it before flowering! It stinks
and although it should be quite harmless (beware, I haven't done extensive research on this, so if you are not sure about health safety, you should do more research and not use it. Being Dutch, I compromised and decided to not use it during flowering), it's supposed to be terrible to smoke. I believe that!
The underside of the leaves and the soil are the most important. Yes, you also need to spray the top of your soil. Fungus gnats e.g. lay their eggs in the soil because their larvae eat the roots. So getting the neem oil into the soil is important.
I take my plant out of my cabinet and somewhere else to spray, so it doesn't get dirty in there. I've read though that spraying the inside of the grow area should also help.
Use it right before the lights go off and make sure it's dry before the lights switch on again. Spray twice a week for two weeks.
During spraying shake vigorously between each spray. This stuff will clog your spray bottle.
Clean the spray bottle thoroughly afterwards. I use soft soap also to clean it. Lots of it and hot water. After I've rinsed the bottle itself I add clean water and soft soap again then put in the spraying mechanism and spray with the hot soapy clean water for a long time. When that's done I spray again with clean water, no soap.
I now this reads as a lot of work, but actually it's not. I'm just high and as a result very focused and like to be thorough when I try to help people. If you decide to give it a go, let me now how it worked out for you!
:smoking: