Bayer Products has a formula that kills aphids. Bayer Complete Insect Killer( walmart usually carries it). Works great! had these suckers pop up about 6 mths ago, they cross contaminate well and any other plant touching an aphid infested plant will also have them. Get this stuff and saturate your grow. Any plants with buds/trics cannot be sprayed. You can keep any infected flowering plants aphid free by simply going in daily/2x's daily and killing them by smashing them with your fingers. Aphids can be born preggers and multiply in 24 hr periods. Nasty fuckers these are!