Square / Rectangular Tank
0 L
Bottom to top. For partially buried tanks, use full tank height.
Round Tank
0 L
Across the top through the centre; height is bottom to top.
Rainwater Collection Estimate
Typical defaults: metal ~0.9, tile ~0.8–0.85.
One-off loss per month to remove initial debris.
0 L / month
Rule of thumb: 1 mm of rain on 1 m² ≈ 1 L. We apply first-flush and runoff defaults.
Have questions?
Quick answers to common questions.
Do I enter tank sizes in metres?
Yes. All tank dimensions here are in metres (m). Rainfall stays in millimetres (mm).
What gets copied when I click “Send to Pure Water”?
We copy the label and the litres (e.g., “Rectangular tank capacity: 7,500 L”). On the booking form, click the tank-capacity field and paste.
How accurate is the rainwater estimate?
It’s a quick guide. We subtract a small first-flush and apply a roof runoff coefficient. Actual capture varies with roof material, debris, and setup.
Can you help size a system?
Yes. Add notes in the booking form and we’ll confirm sizing for your site and use-case.