Self-Adhesive Monotub Filters 38 mm | 12 pieces

If your monotub is on the smaller side — a 6 L shoebox, a modded 10–15 L Sterilite, or any clear food-container build — drilling one or two big holes can dump CO₂ unevenly and leave dead zones at the corners. That's exactly the problem the 38 mm Self-Adhesive Monotub Filter solves. Twelve patches let you scatter 6–10 small FAE holes around the tub, which gives a much more even airflow gradient and reduces aborts in the corners.

This is also the patch we recommend if you're just starting out with adhesive filters and want a forgiving size to learn with — at 38 mm you can re-position a misaligned patch without wasting much surface area, and a drill bit failure leaves you with a small hole that's easy to patch over.

Also available in: 65 mm | 90 mm

Hole pattern we recommend

For a 6 L shoebox: 4 patches per long side (alternating high and low), 1 patch per short side. For a 10–15 L Sterilite: 4 high, 4 low on the long sides plus 1 on each short side. Drill 10 mm holes, alcohol-wipe, peel, press for 30 seconds.

Specifications

• Diameter: 38 mm (1.5")
• Filter media: 0.22 micron polypropylene nonwoven
• Adhesive: pre-applied, autoclavable, water-resistant
• Hydrophobic surface (condensation beads off)
• Pack contents: 12 patches

Best for

Shoebox tek, PF-tek graduates, small monotubs, modded grow bags, fruiting chambers under 20 L.