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What Size Carbon Filter do I need




What Size Carbon Filter Do I Need?

Filter Calculator

Length (ft)

Width (ft)

Ceiling Height (ft)

Total Cu. Ft.

# of Lights

X X = +

Recommended CFM


Use the Filter Calculator above to find your recommended CFM, then find your correct filter size on the chart below. Pay attention to the two different columns, one for scrubbing air in a circle and the other for filtering air through a filter in a single pass.


US Sizing Table


Inches (Metric)


Maximum Scrubbing CFM

Maximum Scrubbing m3/hr

Recommended Single Pass Filtering CFM

Recommended Single Pass Filtering M3/hr

4x8 (100x200) 8 lbs 3.6 kilos 150cfm 250m3/hr 75cfm 125m3/hr
4x12 (100x300) 11 lbs 5 kilos 200cfm 350m3/hr 100cfm 175m3/hr
4x20 (100x500) 18 lbs 8.2 kilos 350cfm 600m3/hr 175cfm 300m3/hr
6x12 (150x300) 15 lbs 6.8 kilos 275cfm 470m3/hr 150cfm 235m3/hr
6x16 (150x400) 20 lbs 9 kilos 375cfm 635m3/hr 200cfm 325m3/hr
6x20 (150x500) 23 lbs 10.5kilos 450cfm 765m3/hr 250cfm 400m3/hr
6x24 (150x600) 27 lbs 12.25 kilos 500cfm 850m3/hr 250cfm 425m3/hr
6x39 (150x1000) 54 lbs 24.5 kilos 800cfm 1360m3/hr 400cfm 680m3/hr
8x24 (200x600) 33 lbs 15 kilos 600cfm 1000m3/hr 300cfm 500m3/hr
8x39 (200x1000) 50 lbs 22.7 kilos 950cfm 1800m3/hr 475cfm 900m3/hr
10x24 (250x600) 39 lbs 17.7 kilos 700cfm 1200m3/hr 350cfm 600m3/hr
10x39 (250x1000) 64 lbs 29 kilos 1400cfm 2350m3/hr 700cfm 1175m3/hr
12x20 (300x500) 40 lbs 18 kilos 850cfm 1450m3/hr 425cfm 725m3/hr
12x24 (300x600) 47 lbs 21.3 kilos 925cfm 1600m3/hr 475cfm 800m3/hr
12x39 (300x1000) 76 lbs 34.5 kilos 1700cfm 2850m3/hr 850cfm 1425m3/hr
12x48 (300x1200) 90lbs 40.8 kilos 2200cfm 3750m3/hr 1100cfm 1875m3/hr
14x39 (350x1000) 86 lbs 39 kilos 2100cfm 3550m3/hr 1000 cfm 1775m3/hr
14x48 (350x1200) 104 lbs 47 kilos 2500cfm 4250m3/hr 1250cfm 2125m3/hr