In water and wastewater duty, filter bags earn their keep two ways: protecting the expensive stuff downstream (membranes, carbon beds, UV) and getting discharge water under the permit limit. Bags are the lowest-cost format per gallon for both jobs — and when the problem is oil in the water, we make a bag that solves it in the housing you already have.
What We Recommend
| Application | Media | Typical starting point |
|---|---|---|
| Pre-filtration ahead of RO / carbon / UV | Felt, polypropylene | 5–25 µm |
| Compliance polishing before discharge | Felt | 10–50 µm |
| Oily water — tramp oil, wash-down water, condensate | Oil Magnet® oil-absorbing bags | Pulls free & mechanically emulsified oil while filtering solids |
| Grit / coarse solids ahead of finer stages | Mesh (washable) | 100–800 µm |
| Groundwater remediation / pump-and-treat | Felt or Oil Magnet® | 10–50 µm |
Practical Notes
- Stage it. A coarse bag ahead of a fine bag almost always beats one fine bag — the coarse stage takes the load, the fine stage takes the credit. See the sizing guide.
- Oil is a special case. A standard felt bag passes oil straight through. If the discharge issue is sheen or oil & grease numbers, that’s an oil-absorbing bag problem, not a micron problem.
- High solids loads favor size 2 bags for surface area, and duplex housings so one side stays in service during change-out.
Working against a permit limit? Call 800-554-8555 or request a quote with the flow rate and what’s in the water.