What does a dehumidifier do?

When the air humidity exceeds the ideal range, a dehumidifier removes moisture from the air, reducing the humidity and ensuring your plants remain in an optimal environment. Excessive humidity can lead to bud rot and other molds, and can also slow plant growth.

What size dehumidifier do I need for my grow room?

This depends on how much water you use. Suppose you are growing 6 plants in a 4x4 grow tent, watering them every 2 days with 1 gallon (8 pints) per plant each time. You can calculate the dehumidifier size as follows:

Step 1: Calculate the total water used each time

• 6 plants * 1 gallon/plant = 6 gallons

Step 2: Convert gallons to pints

• 6 gallons * 8 pints/gallon = 48 pints

Step 3: Calculate the average daily dehumidification

• 48 pints / 2 days = 24 pints/day

Step 4: Consider low temperature and low humidity areas (reduce by 15%)

• Basic requirement: 24 pints/day
• Adjusted requirement: 24 pints * 0.85 (estimate 15% reduction for low temperature and low humidity)
• Adjusted requirement calculation: 24 * 0.85 = 20.4 pints/day

Step 5: Consider high temperature and high humidity areas (increase by 15%)

• Basic requirement: 24 pints/day
• Adjusted requirement: 24 pints * 1.15 (estimate 15% increase for high temperature and high humidity)
• Adjusted requirement calculation: 24 * 1.15 = 27.6 pints/day

Why recommend a compressor dehumidifier over a semiconductor dehumidifier?

Compressor dehumidifiers are much more effective than semiconductor dehumidifiers, with a dehumidifying capacity 39 times greater. You may have previously purchased a semiconductor dehumidifier only to find it almost ineffective. This is why we recommend compressor dehumidifiers: they quickly process large volumes of air, provide better dehumidification, and are highly efficient.

What should the humidity be in a grow room?

While the key to successful growing is VPD (Vapor Pressure Deficit), generally, seedlings and clones require high humidity of 70-75%. As plants grow, gradually reduce humidity to 50-70%. During flowering, further reduce humidity to 40-50% and maintain this range until harvest.

All indoor growing systems benefit from a dehumidifier, but it is especially important for hydroponic systems. Proper ventilation also helps control humidity, so make sure to install fans or blowers.

Other factors to consider

If your room is sealed and equipped with an air conditioner, the air conditioner will remove some moisture. Check how many pints of moisture your air conditioner removes daily and subtract this amount from your daily dehumidification needs.