Photosynthesis is the process by which plant leaves make carbohydrates. Sunlight, CO2 and water are converted into carbohydrates and O2 by the action of chlorophyll in the chloroplasts of the plant. Plants growing indoors under artificial light often lack enough CO2 to efficiently photosynthesize. When plants are able to maximize the process of photosynthesis, the result is larger plants with larger yields. ExHale can be used for both vegetative plant growth as well as for fruit and flower production. ExHale cultivates CO2 24 hours a day with no need to refill bottles or use expensive CO2 production units. The power of ExHale lies in the mycelial mass inside the vented cultivator. This mycelial mass cultivates CO2 and the one-way breather patch releases CO2 continually for up to 6 months. ExHale comes complete and is cultivating CO2 even before you get out of the checkout line. No need to turn it on or turn it off, simply place ExHale in your grow space and leave it alone to do its job. The ExHale Cultivator is designed for small to medium grow spaces, or more specifically 1 ExHale Cultivator will provide 4-6 plants with the CO2 they need. A continuous shower of CO2 directly onto your plants is the most efficient way to deliver CO2. Placing the ExHale Cultivator slightly above the level of your plants will insure they receive the CO2 they need 24 hours a day for up to 6 months. Replace by date on bag is the retailer must be sold by date for the customer to achieve 6 months of Co2.