Optic Foliar ATAK is the only control spray against Powdery Mildew on the market that can be applied with the lights on with no damage or burning to the leaves or flowers. Comprised of copper sulphate and organics; ATAK is safe to use into late bloom up to one week before harvest and will not leave any trace chemicals within the plant at harvest. ATAK can be sprayed with the lights on, no damage or burning to the leaves and no residuals to wash off! Optic Foliar ATAK is the only fungus product on the market that guarantees no damage to the leaves while providing safe nontoxic results that leave nothing within the plant that will affect the taste or the quality of crops.