
What a Horti-Control Dust Shroom 8 in Actually Filters
Most filtration in a grow room points outward, and this one points inward. A carbon filter stops odour leaving, while this stops particles arriving. Media is open-cell foam, designed and built by UNI Filter in Fullerton, California. It arrives pre-oiled in a sealed bag, which is how an oiled-foam filter is meant to work. Oil on the foam strands catches fine particles rather than the pore size alone doing it. Capture is 99.9 percent of particles down to 0.1 micron. It is not a HEPA certification. A certified HEPA filter is rated at 99.97 percent at 0.3 micron under a defined test. There is zero CFM loss, measured on Can Fan high-output inline fans. Any filter adds some restriction, so treat that as a best case with a clean filter. This version fits 8 in ducting, and the range runs from 4 to 12 in.
Keeping Pre-Oiled Foam Media Working
Pre-oiled foam media is the part people get wrong, and it is simple once known. The oil does the filtering, so a washed filter with no oil on it filters very little. Wash it with foam air filter cleaner rather than with detergent. Detergent strips the foam and leaves it brittle after a few cycles. Dry it fully, then re-oil with foam air filter oil until the foam is evenly tacky. Squeeze out the excess rather than leaving it dripping, because surplus oil restricts airflow. How often depends entirely on the site. A dusty rural intake may need it monthly, and a filtered indoor room twice a year. Check it by eye and by airflow rather than by the calendar. A loaded filter shows as a grey surface and feels like a drop in intake velocity. Washed and re-oiled on that basis, a foam filter lasts years. Left dirty it becomes exactly the restriction it is meant to avoid.
Key Features
- An intake filter: It stops particles arriving, where a carbon filter stops odour leaving.
- Washable and re-oilable: Foam air filter cleaner and foam filter oil, rather than detergent.
- Pre-oiled on arrival: Oil on the foam strands is what catches the fine particles.
- Capture rate: 99.9 percent of particles down to 0.1 micron.
- Not a HEPA certification: Certified HEPA is 99.97 percent at 0.3 micron under a defined test.
- Zero CFM loss: Measured on Can Fan high-output inline fans.
- Made by UNI Filter: Designed and built in Fullerton, California, and marked patent pending.
- Five sizes in the range: 4, 6, 8, 10 and 12 in, with this one for 8 in duct.
Technical Specifications
| Specification | Value |
|---|---|
| Brand | Horti-Control |
| Product | Dust Shroom foam intake filter |
| SKU | 204008 |
| Duct size | 8 in |
| Media | Open-cell foam, supplied pre-oiled |
| Made by | UNI Filter, Fullerton, California |
| Capture | 99.9 percent of particles 0.1 micron and larger |
| Airflow | Zero CFM loss on Can Fan high-output fans |
| Washable | Yes, with foam air filter cleaner |
| Re-oiling | Foam air filter oil, applied until the foam is evenly tacky |
| Patent | Patent pending |
| Sizes in the range | 4, 6, 8, 10 and 12 in |
| Case pack | 6 units for this size |