T40F Vanishing Water

Vanishing water system sizing on a T40F filter tank

Follow steps 1 → 4

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) × H^3/2

Waterfall Width (L)

Width of the waterfall opening

Water Depth Over Falls (H) 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

Stream Channel Dimensions

Windows B · C · D · E · F

B — Waterfall Weir Rock Thickness

Enter the thickness of the weir rock (inches)

inches

C — Total Water Depth in Stream Channel

Auto-calculated: Water depth over falls (A) + Rock thickness ÷ 1.714 (B ÷ 1.714)

Combined Depth (A + B) — inches

D — Stream Channel Width

Width of excavated channel before liner (feet)

E — Stream Length

Total length of the stream (feet)

F — Total Gallons in Stream

Auto-calculated: C × D × E (converted to gallons)

Stream Volume — gallons

Vanishing Pool (Optional)

Windows G · H — Skip if no vanishing pool

G — Vanishing Pool Surface Area

Square feet of 3" deep vanishing pool (leave blank if none)

sq ft

H — Total Gallons in Vanishing Pool

Auto-calculated: G × 0.25 ft deep × 7.48 gal/ft³

Vanishing Pool Volume — gallons

Containment Results

Windows I · J — Total gallons and product configuration

I — Total Containment Required — gallons

Breakdown

Stream volume (F) —

Vanishing pool volume (H) —

J — Product Configuration

—

Additional Recommended Products

Based on Waterfall Flow (Window A) GPM

Also Recommended

WS1 — Waterfall Starter

PS1 — Pump Shut-Off

K5 — Auto-Fill Assembly