Quick Answer: Which BIGFOOT® model is safer near 40 GPM?
40G fits pumps comfortably under ~40 GPM in moderate debris. 80G is usually the safer pick near the line, in heavier algae, or when you need longer intervals between clean-outs.
BIGFOOT® is a suction-side intake filter family built for surface-water irrigation pumps drawing from lakes, ponds, rivers, or retention basins. It reduces intake velocity by spreading suction across a wider screen area, which helps reduce clogging while protecting the pump.
Model comparison
Model
Best for
Typical notes (verify)
BIGFOOT® 40G
Pumps <~40 GPM, moderate debris
Smaller screen footprint; more frequent clean-outs during algae spikes
BIGFOOT® 80G
Higher flows, heavy organics, longer intervals
More screen area; typically safer choice near the 40 GPM line
Dual 40G (Series)
Shallow-water or algae-heavy intakes
Two 40G assemblies inline; sealing and restriction management are critical
Selection logic
How to choose between 40G and 80G
Choose for actual flow, debris load, and maintenance tolerance, not just the nominal pump label.
40G: best when flow stays comfortably below ~40 GPM and debris load is moderate.
80G: stronger fit when the source carries heavier algae or the system runs near the upper boundary.
Dual 40G: field-usable in some submerged builds, but only when sealing quality and cleaning discipline stay high.
Service-first rule: confirm intake placement, suction-side sealing, and actual pump flow before changing heads or schedules downstream.
Field note: dual BIGFOOT® 40G inline (series) — fully submerged
We have successfully run two BIGFOOT® 40G filter assemblies inline (in series) as a fully submerged intake (mostly horizontal; one deployment vertical on a steel seawall on Lake Erie), using synthetic filter media matting.
Typical sequence (as built):
Drawline (1½", 2", or 2½") → male adapter → PVC check valve → 2" × 6" PVC threaded nipple → BIGFOOT® 40G Filter A → 2" × 6" nipple coupling → BIGFOOT® 40G Filter B.
Optional: brass 2" foot valve installed inside Filter A on some builds (verify compatibility and serviceability).
Critical cautions
Air leaks kill suction: every threaded suction-side joint must seal perfectly.
Restriction compounds: two filters in series can reduce flow as media loads—monitor and clean.
Valve stacking: avoid check/foot valve conflicts and keep servicing practical.
Placement and maintenance
Keep the intake off the bottom to avoid silt loading.
Inspect after early runs; algae season can load screens rapidly.
Clean screens/media as needed—bigger intake area generally means longer intervals.
Best next step
Use these next when this field guide points toward a real inspection, repair, upgrade, or ROI decision for the property.