Don't foliar feed unless you're having nutrient uptake problems.
& never during flowering unless you want moldy buds (from what I've heard)
What??? Do you people make this stuff up? For decades I've been foliar feeding in conjunction with soil grows, hydro grows, aeroponic grows and drip grows. During FLOWERING AND DURING VEGATIVE . If one has adequate ambient conditions and adequate airflow, mold is usually a non issue. People can have mold issues without foliar feeding if the humidity is to high and poor airflow.
Cyphen,
I suggest getting a decent organic or mostly organic pre made foliar spray such as Bills Perfect fertilizer (its like $5 a bottle) as a stand alone foliar application, or use it with Spray-N-Grow, just follow the dosage instructions and don't exceed the recommended dosage. You could also use Chi foliar spray or whatever you decide on. One good tip is to use
'like products', for example, if you use General Hydroponic nutes in soil or via Hydro, its always a good idea to stick with the products that are made by the same manufacturer, I just used General Hydroponics as an example, since they have
excellent feeding schedules and show you what products supplement the others. I just linked to one, there are more at that site. If you scroll down, you will see the soil feeding schedule recommendations.
I've been using General hydroponic nutes for my personal garden for more than 25 years, when I was 18 I grew my first plant in a Phototron, then as I learned, I migrated to ebb and flow, back then the choices were limited, many of us made our own systems. Today, the choices are endless.
Been using GH nutes pretty much exclusively for my personal needs for many moons, I've had great success with using Bills perfect fertiliser as a supplent foliar application in conjuntion with the GH nutes. There are a TON of nute products on the market these days, I figure, if it ain't broken, theres no need to deviate from what has given me excellent results time after time and year after year. I've tried other johnny come lately products, but always came back to GH.
Bottom line is this; You should use whatever product you feel comfortable with, everyone has their own preferences.
Maybe others will chime in to help you brew your own foliar spray. Hope this info helps. Good luck with your grow.