Design tanks that protect pumps and emitters well. Compare depth, area, and length ratios fast. Download results as files for field teams quickly now.
| Flow | Detention | Overflow | Depth | L:W | Area | Length | Width |
|---|---|---|---|---|---|---|---|
| 8 | 25 | 1.2 | 1.0 | 3 | 6.667 | 4.472 | 1.491 |
| 12 | 30 | 1.0 | 1.2 | 3 | 12.000 | 6.000 | 2.000 |
| 20 | 40 | 0.8 | 1.5 | 4 | 25.000 | 10.000 | 2.500 |
Settling tanks protect gardens and drip systems by removing grit, silt, and organic flocs before water reaches filters and emitters. Clearer water reduces clogging, keeps pressure uniform, and limits maintenance time. For ponds, rain barrels, or canal supplies, a dedicated settling stage also stabilizes turbidity after storms and irrigation flushing.
Sizing starts with flow rate because every liter must spend enough time inside the tank for particles to fall. Detention time defines how long water remains in the basin, while sludge allowance reserves space for accumulated solids between cleanouts. When the allowance is too small, solids re‑suspend and clarity drops during high demand. Typical garden intakes use 15–60 minutes depending on sediment load, with higher times for fine silts.
Overflow rate links surface area to performance. A lower surface overflow rate gives particles more opportunity to settle, especially fine silts and algae aggregates. The calculator checks area by overflow and area by volume, then uses the larger value so both settling physics and storage requirements are met under typical operating conditions. If the source is very dirty, choose a conservative overflow target and recheck dimensions after field observations.
Tank geometry matters for practical installation. A higher depth can reduce footprint, but excessive depth may complicate access and increase structural needs. Length‑to‑width ratio promotes smooth plug flow, helping solids move to the bottom without short‑circuiting. Freeboard adds safety against surges, wind setup, and foam, preventing spills near beds. Rectangular tanks are easy to build from blocks, while round tanks can simplify mixing control and cleaning.
After sizing, focus on operation. Place inlet and outlet baffles to slow incoming jets and keep floating debris away from the outlet. Schedule desludging based on observed sludge depth, not only calendar time, and record cleanout volumes for future adjustments. Pair the tank with a screen or media filter for complete protection. A simple sight tube or dipstick can track sludge buildup and confirm that the chosen allowance matches reality reliably.
Many small systems perform well at 15–60 minutes. Start higher for canal water or storm runoff. Validate by observing outlet clarity during peak flow, then adjust the target time if solids still pass through.
Use both. Detention volume ensures time and storage, while overflow rate controls settling performance at the surface. The larger required area typically governs, especially when fine silts are present.
Clean when sludge occupies a noticeable fraction of working depth or clarity drops. A simple dipstick check works. More frequent cleanouts are common after storms, pond turnover, or heavy irrigation flushing.
Yes, within practical limits. Deeper tanks lower plan area, but very deep basins can be harder to build, inspect, and clean. Always recheck overflow rate so performance is not compromised.
Higher ratios encourage smoother flow and reduce short-circuiting, which helps particles settle instead of rushing to the outlet. Ratios around 2:1 to 4:1 are often practical for rectangular tanks.
Usually, yes. Settling removes heavier solids, but fine particles and organics can remain. A screen or media filter downstream protects emitters and valves and extends time between maintenance cycles.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.