Water — Use a jet of water to blast whiteflies and wash them off your plants and leaves. You should then rub a weak solution of insecticidal soap onto the leaves in the late afternoon. Repeat this process every week to control and get rid of whiteflies.
Note from Gail: This is what I use to remove whiteflies, but I don’t use the insecticidal soap on my Aquaponic system. Use your hand as a ‘backup’ for the plant then spray the leaves using the hose on ‘shower’ mode. I do this 2-3 times/week until the whiteflies are gone.