Dewi, If you are just fighting aphids, All you need is 1 tbsp of cheap liquid dishsoap in a gal (4L) Apply with a plant mister, esp under the leaves. Allow it to sit for about 20min to 1/2 hour and then rinse with some room temp. water. Gotta do it weekly, from spring thaw to fall freeze. You don't need to waste any chiles L.B.