Between 40~60%. Yeah i have 5 fans. It was werry hot weather for about 3 days outside was +33 in celcius. They were sleeping in +26~30 celcius. How to get rid of mildew? Some one told me baking soda or something could help?
What do you mean?Yea, it looks like powdery mildew. I'd consider hitting it with UV.
Hit your plants with UV light at night. UV light is what will kill powdery mildew. Unfortunately the fungus spores are in the environment. I've never personally had it but I have known others who have, nothing else has worked other than UV. The only sure way to clear the spores in your environment would be to use something like Ozone. Might be worth considering a fungicide as well.
If it were spider mites the tell tale signs are speckled dots on the tops of the leaves where they're underneath chowing down. They also start webbing from underneath. Easy way to tell is to flip the leaves over, you can see the adults without a microscope.
I found a lot of different lamps and pricing, maybe you could recommend something particular? Maybe some one who already used thos metod could recommend something particular?