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💧Filtrific®
At Grade Pool
T75F Sizing & Component Calculator
Follow steps A → FA
Waterfall Flow Calculator
Enter waterfall width and water depth to calculate GPM
📐 Rectangular Contracted Weir Calculator
Enter the waterfall width (L) and the water depth flowing over the falls (H) to calculate the waterfall GPM. Formula: Q = 3.33 × (L − 0.2H) × H3/2
Depth of water flowing over the weir, in inches
⚠️ Please enter valid values for L and H.
Calculated Waterfall Flow
—
GPM
Formula: Q (cfs) = 3.33 × (L − 0.2H) × H3/2 |
L = waterfall width (ft) | H = water depth over weir (ft) |
GPM = Q × 448.83
✓ Waterfall GPM (A)
—
GPM
▼
B
Pool Surface Area
Enter square footage of the pool surface
square feet
▼
C
Pool Circulation GPM
0.15 GPM per square foot of pool surface (auto-calculated)
Circulation (B × 0.15)
—
GPM
▼
D
Total Waterflow GPM
Waterfall (A) + Circulation (C)
Total Flow (A + C)
—
GPM
▼
E
Number of Skimmers
S2 series max 25 GPM each · S3 series max 60 GPM each
S2 Series
—
25 GPM max each · 4.5″ weir
S3 Series
—
60 GPM max each · 10.672″ weir
▼
F
Skimmer Depth Calculator
Water depth over the skimmer weir — calculated from Total Waterflow (D) and weir width
S2 Series — 4.5″ weir
—
inches of water depth over weir
S3 Series — 10.672″ weir
—
inches of water depth over weir
📦 Product Configuration
If Using S2 Series Skimmers
Filter · Skimmers
1 × T75F
—
If Using S3 Series Skimmers
Filter · Skimmers
1 × T75F
—
⭐ Additional Recommended Products
K5 — Auto-Fill Assembly
PS1 — Pump Shut-Off / 120V
PS2 — Pump Shut-Off / 220V