How to connect ventilation to a growbox?

Effective plant cultivation in a grow tent requires providing them with an optimal microclimate. Fortunately, this is not a problem. It's all about composition, humidity, temperature, air movement, and lighting. All these factors can be provided to the plants by using appropriate lamps, a ventilation system, and supplying the necessary carbon dioxide for photosynthesis. How to do this?

Ventilation to Remove Excess Moisture
Air exchange is crucial, especially since moisture constantly accumulates in it from the plants and their substrate. Therefore, it's necessary to remove this excess moisture outdoors. Regardless, plants must be provided with a supply of CO2.

To achieve this, it's essential to ensure ventilation holes, remembering that warm air travels up and cold air down. Therefore, the inlet should be at the bottom and the outlet at the top, where the air heated by the lamp accumulates. A complete grow box set comes with such openings, but in DIY setups, they need to be made manually, ideally diagonally across the tent, selecting the diameter to match fans and ventilation ducts.

Ventilation – Forced Only
Apart from bringing in and taking out air, it's good to ensure its movement and circulation within the grow box. A standard room fan, mixing the air, will ensure this. Not only will this improve the air quality at every point of the grow box, but it will also strengthen the plant stems.

Basic ventilation in the grow box can be provided by duct fans or radial fans. Their capacity, measured in cubic meters per hour, should be chosen so that they can exchange all the air within five minutes. Calculating the grow box's volume is straightforward; just select an appropriate fan. Some base this on the lighting power, recommending that the fan's capacity in m³/h should be 2/3 of the HPS lamp's power. This calculation is advisable if there's a risk of overheating the plants. However, if using lighting that generates little heat, the earlier mentioned ratio would be better.

Extraction and Odor Elimination
An exhaust fan should be installed at the top opening, keeping in mind protection against excessive vibrations and noise. Acoustic dampers may be necessary, installed both before and after the fan. Its operation should not be troublesome for anyone, especially at night, when every working device can be heard from afar.

It's also important to remember that a grow tent is a place where intense, sometimes irritating odors can accumulate. Therefore, a complete grow box set is worth enhancing with carbon filters, which will ensure their absorption and elimination. Ideally, install the filter before the fan. The filter's capacity should exceed the fan's capacity. Of course, connect the individual components with ventilation ducts of matching diameter. If it's not possible to gather everything of the same diameter, reducers, adapters, and hose clamps will be necessary. The tightness of connections is extremely important.

What About Carbon Dioxide?
However, grow tents also require a supply of CO2. There are several ways to supply plants with the carbon dioxide necessary for photosynthesis and lush growth. The most effective, though not the simplest (or cheapest), method would be CO2 emission from a cylinder. However, this installation is recommended for those with a bit more technical knowledge, who can handle a cylinder, reducers, manometers, etc.

Much simpler to use are biological kits with an electric pump and distribution hose. Their installation won't pose a problem to anyone. Also, the distribution of carbon dioxide is very easy in their case. Always remember that CO2 is a gas heavier than air, so the outlets of the hoses should be located above the plants so that the gas falls on them from above.

There are also tablets for dissolving in water, which generate CO2, special mats, and bags. A popular and very cheap method is the so-called "moonshine," well known to aquarists. This is simply a bottle, usually two liters, filled halfway with water with about 150 mg of sugar and a cube of yeast. The bottle is corked, in which a distribution hose is placed, and hung above the plant.