Ventilation and air movement are two of the most neglected and misunderstood factors of an indoor hydroponics grow room.
The simple truth is if marijuana grow room air is stagnant and unmoving, your plants have a harder time “breathing.” This slows their growth and can create an environment that favors diseases and pests.
If your grow room air doesn’t move around so that your cannabis plants’ stems and stalks are moved by air, your plants will be structurally weak. This means you lose density and structure that can support heavier buds.
Just think of the amount of fresh air and air movement plants get outdoors, and then compare that to what plants experience sitting in a room if the room has no aeration fans, vent fans, air scrubbers, or other air management.
That in itself gives you a basic guide to what you may need to change about your indoor marijuana grow room.
Perhaps the most important factors you face as an indoor marijuana grower are excess heat and humidity. Unless you’re growing with LED or fluorescent lighting (which are only good for autoflowering or other small-scale marijuana plants), your indoor grow room will get very hot.
HID and plasma lights, which are the preferred grow lights for professional marijuana growers, are going to generate more heat than your room can handle, unless you have cooled/vented lights.
Without venting, fresh air, air conditioning, or dehumidification, your indoor grow room will almost certinaly have too much humidity too.
Take a look at this guide to ideal indoor marijuana growing conditions and you’ll see the temperature and humidity ranges your cannabis plants need.
If you’re growing in an enclosed space and not using vent fans and other controls, you won’t have those ideal conditions, and your plants won’t grow as well or produce as much bud.
To remove heat, you can run vented lights, and/or exhaust/vent fans. You can run the fans 24/7, only when the lights are on, or only when you’re NOT adding C02 into your hydroponics grow room.
I suggest you ask your hydroponics store about automatic controllers that’ll turn your fans and other climate control equipment on and off for you. You should also ask about grow room climate control in general.
In many cases, hydroponics cannabis growers install dedicated climate monitors, air conditioning, dehumidification, and heating units that are solely for the grow room.
The fact is, the marijuana grow room should be a totally controlled environment that is set apart from the environment in the rest of the building that the grow room is in.
Another benefit of marijuana grow room climate control is that you control vectors in and out. This means you aren’t sending marijuana smell outdoors (because you’re filtering your exhaust air).
And you aren’t taking unfiltered, potentially contaminated air into your grow room.
Just remember, if you are adding C02, you don’t want to run vent fans at the same time as you’re adding C02, because they’ll take the C02 out of the room along with the room’s other air components.
The main image I have for you to remember is: look at cannabis plants outdoors and see how they move in the breeze.
Imagine the constant flow of oxygen, C02 and other atmospheric elements that keep them breathing well. Then try to duplicate that in your indoor marijuana grow room.