How to Inspect Your HEPA Filter (And Why It Matters)

Your flow hood is only as good as its filter.

A damaged or clogged H13 HEPA filter means reduced filtration efficiency — particles that should be captured are passing through into your work zone. You won't see it happening. You'll see it three weeks later when a jar goes wrong for no obvious reason.

Here's how to inspect your Steriflo filter and know when it needs replacing.

What to Check When Your Unit Arrives

HEPA filters can be damaged in transit. Before your first session, take 2 minutes to check.

Press the spring-loaded latch and open the filter assembly. Remove the pre-filter (the outer foam layer) and examine the H13 HEPA filter behind it. Look for:

→ Tears or punctures in the filter media
→ A bent or crushed frame
→ Gaps between the filter edge and the housing
→ Visible compression damage from shipping

If you find any damage, contact us before using the unit. A compromised filter doesn't just underperform — it can give you false confidence. You'd be moving air without adequate filtration while believing you're protected.

During Normal Use — What to Watch For

The pre-filter is your first line of defense. It catches larger particles before they reach the HEPA layer, which extends the life of the more expensive filter behind it. Check it every 3 months. If it's visibly grey, discolored, or feels dense when you compress it, replace it.

The H13 HEPA filter itself should be checked every 6 months. Signs it needs replacement:

→ Visible discoloration or grey deposits across the filter face
→ Airflow output that feels noticeably reduced at the same speed setting
→ Any physical damage discovered during inspection

A simple way to check airflow: hold a thin piece of tissue paper 6 inches in front of the filter on Low speed. It should be held gently but firmly in place by the airflow. If it droops or flutters inconsistently, airflow has dropped.

Replacement Intervals

Under normal home cultivation use (1–2 sessions per week):
→ Pre-filter: every 3–6 months
→ H13 HEPA filter: every 12–18 months

Under heavier use (daily sessions or small commercial operation):
→ Pre-filter: every 6–8 weeks
→ H13 HEPA filter: every 6–12 months

Environments with higher ambient particle counts — near construction, in dusty workshops, in areas with high pollen — will shorten these intervals. When in doubt, replace the pre-filter first. It's inexpensive and it protects the main filter.

Replacement Is Tool-Free

Press the latch. Open the assembly. Swap the filter. Snap it closed. Two minutes, no tools.

Replacement pre-filters and H13 HEPA filters for Steriflo are available at gro-myco.com.

Questions about your filter or your unit? Email us at mailto:hello@gro-myco.com.