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💧Filtrific®
T390F Pond and Stream Sizing
Follow steps 1 → 41
Waterfall Flow Calculator
Calculate GPM and capture water depth over the falls
📐 Rectangular Contracted Weir Calculator
Enter the waterfall width (L) and the depth of water flowing over the falls (H). 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 (both must be greater than 0).
Calculated Waterfall Flow
—
GPM
✔ Waterfall Flow (Window A)
—
GPM
2
Stream Channel Dimensions
Windows B · C · D · E · F
Enter the thickness of the weir rock (inches)
inches
Auto-calculated: Water depth over falls (A) + Rock thickness ÷ 1.714 (B ÷ 1.714)
Combined Depth (A + B ÷ 1.714)
—
inches
Width of excavated channel before liner (feet)
ft
Total length of the stream (feet)
ft
Auto-calculated: C × D × E (converted to gallons)
Stream Volume
—
gallons
3
Pond Reservoir Calculator
Windows G · H — Pond surface area, circulation & total skimming flow
💧 Pond Reservoir Details
The pond acts as a reservoir during startup. Based on a 1½" allowable pond surface drop and the available water height above the skimmer (max 3"), the pond contributes gallons that offset the total containment required.
Total surface area of the pond (square feet)
sq ft
Circulation = 0.15 × Pond Surface Area
Waterfall GPM + Circulation GPM · S64 for flows up to 80 GPM · S66 for flows 81 – 200 GPM
4
Containment Results
Windows I · J — Net containment and recommended product configuration
I — Net Containment Required
—
gallons
Breakdown
Stream volume (F)
—
Pond reservoir credit
—
Net containment required
—
J — Product Configuration
With the pond reservoir credit
—
Without the pond reservoir credit
—
+
Additional Recommended Products
Based on Waterfall Flow (Window A) GPM
Also Recommended
WS1 — Waterfall Starter
PS1 — Pump Shut-Off
K5 — Auto-Fill Assembly