Optic Foliar Switch 4 Liters / 1.05 Gallon Optic Foliar Switch works best when used with Optic Foliar Transport at a rate of 10ml/litre or 2 teaspoons/quart (40ml/4litres or 8 teaspoons/gallon) Shake vigorously after adding Optic Foliar Transport. After adding Optic Foliar Transport, product must be sprayed onto plants within 15 minutes. Spray plants on day 7 & 17 of bloom cycle or at the first sign of flower stress. Can be sprayed with lights on. Do not adjust pH of solution. Avoid spraying on electrical equipment.