Using Odour Neutralisers in a Grow Room

Emporium Hydroponics • January 30, 2026

Here’s how to use them properly without hurting plants or wasting money.

Managing smells in a hydroponic grow room neutralisers work best as backup. Use them properly without hurting plants or wasting money.

First and foremost, regulate the airflow then manage smells in a hydroponic grow room with the neutralisers. Neutralisers work best as a great backup with the main line of defence.


1️⃣ Get the basics right (before neutralisers)


Before adding any odour product, make sure you have:

  • Inline exhaust fan pulling air out of the room
  • Carbon filter attached to that exhaust
  • Slight negative pressure (walls/tent gently pulling inward)

👉 If smells are strong, a neutraliser alone won’t save you. Fix airflow first.


2️⃣ Choose the right type of odour neutraliser

  • Gel or bucket neutralisers (ONA-style, enzyme-based)
  • Passive absorption bags
  • Enzyme-based sprays (for surfaces only)

These neutralise odours chemically instead of masking them.

❌ Avoid

  • Incense or scented candles
  • Aerosol air fresheners
  • Essential oil diffusers inside the grow room

Strong fragrances can:

  • Stress plants
  • Affect taste/aroma
  • Stick to buds or leaves


3️⃣ Placement matters (this is where most people mess up)

Never place neutralisers inside the grow room or tent.

✔ Best placement:

  • Outside the grow room door
  • In the exhaust air path after air exits
  • In hallways, closets, or intake-adjacent spaces


Why?
You want to neutralise smell after it leaves the plant environment, not before.

📌 Rule of thumb:
If your plants can smell it, it’s too close.

4️⃣ How much to use

  • Start with less than the label recommends
  • Increase gradually if odour escapes
  • Replace gels every 3–6 weeks (or sooner if dried out)


Too much neutraliser can:


  • Leak fragrance back into intake air
  • Cause headaches
  • Raise humidity slightly


5️⃣ Use neutralisers as a support system

Best combo looks like this:

  • Carbon filter = 90% of odour control
  • Neutraliser = last 10% insurance

They’re perfect for:

  • Door openings
  • Late flowering stages
  • Harvest days
  • Trim sessions


6️⃣ Extra pro tips 🌱

  • Keep temps below 26°C / 79°F (heat increases smell)
  • Control humidity (high RH = stronger odour spread)
  • Replace carbon filters every 9–18 months
  • Clean spills, dead roots, and standing water (they smell too!)


Feel free to tell us your....:

  • Grow room or tent size
  • Whether odour is escaping all the time or only at certain stages


And we will help to find the best solution!