Spider mites and powdery mildew preventer?

Never use neem oil on budding flowers, It can ruin the taste and flavor. Never had spider mites so all I can say is what the internet tells me. dish soap( NOT detergent ) and water will control them. As for powdery mildew what I like to use is potassium bicarbonate. I have had the best results with it and have even gotten rid of it completely in some cases. Its completely safe for your plants and some people add it to their foliar feed spray as a preventative. Happy Growing

Mycos and Fans 😋 (The Fungi/bacteria kills the Eggs and is good for the Plant in many ways and the Fan is just so you get a nice circulation in the tent so the Dew cant form in the first place) Use Neem if you got the Pests already... my 2 Cents since you got some good answers already.

If you're not in flowering state (I forget to add it) you should spray the plants every 7 days with a combination of neem oil (or neem cake), potasium soap (15g*L) and cold water (at the temperature of your tap)

I would recommend to use a silica product because you're IMHO in the limit to use it, I prefere use it in root aplication it'll thicken the stems, leaves and boost the secondary signals in plants that absorb it to improve the chemical response of the plant from agresions, some people don't use Si in the entire flowering period, others will use it till they reach 4th weeks, others even use it till they need to clean roots to remove excess salts. IMHO I'll use it (in flowering) till their preflowering end. You can use neem cake in the same way to improve the resistance that azadirachtin provides, the mites that eat from your plants will be affected by ingestion and will help to control the plague and force them to look for other source of feeding They like heat and arid clima, so mantain at least 50% RH and low the temp of the top to 23º-24, the ideal conditions for infestation are 30ºc and 35% RH, they'll complete a cycle in 7 days, if you lower the temp to 24º and 50%hr they will complete the cycle between 18 to 22 days. Keep N in control while you veg them, over feed plants with N are more atractive to them so if you have a healthy amount of N you'll have less impact too.

The best way to prevent spider mites is to mix in 2 gallon sprayer 1.5 oz neem oil, 1 oz organicide, 20 ml dr bronners peppermint soap, mix in 1 gallon hot water, then add 1 gallon cold water spray every 5 days during veg this will also protect against mildew. Spray underside of leaves every leaf, start at bottom then make your way up the plant using a fine mist spray pattern then once all plants are sprayed under then spray the top last, mites hatch every 4 days above 74 degrees and up to 30 days below 74 degrees, you can spray plants up to 7 days into flower, never think your plants don’t have mites once you notice you have them. All unfertilized eggs are male all fertilized eggs are female. It only takes a single female she will be mated by her own sons, then begin to lay female eggs. You can go months before you notice them but they are still there, it takes 25 to 30 days of spraying before you can be sure they are gone. That’s 5 to 6 times every 5 days over the course of 25 to 30 days.

I use a little dawn soap in water and spray the undersides of the plant first then the top sides. You can do this through bud without any I'll effects. I find 2 weeks to rid mites if their bad. It kills all that get sprayed but then you need to repeat to kill hatching eggs. For PM I use 40 parts homogenized milk to 60 parts water to control the mildew. This is not a cure just manages it. You need to repeat as neccessary.