Irrigation Reservoir Size Calculator

Plan irrigation reservoir capacity

Enter plant count, average daily irrigation per plant, the desired refill interval, and a reserve percentage. The calculator multiplies daily use by plants and days, then adds the selected allowance.

Eight plants using 1.5 liters each per day require 36 liters across three days. A 20% reserve produces a suggested working volume of 43.2 liters.

Working volume versus tank size

A reservoir’s advertised capacity may include space that cannot be used because of pump intake height, fittings, sloped bottoms, or the need to prevent overflow. Choose a physical container larger than the calculated working volume and confirm usable capacity.

Daily demand changes

Plant size, environment, substrate, irrigation frequency, and runoff strategy can change water use throughout a cycle. Use real irrigation records when available and recalculate during periods of higher demand.

Water quality and maintenance

Long storage times can affect temperature, dissolved oxygen, pH, and solution stability. Keep reservoirs clean, protected from light, and compatible with nutrients and cleaning products. Follow product guidance for mixed-solution storage and circulation.

Planning tips

• Include line and filter volume where relevant.
• Allow room for mixing without overflowing.
• Set a low-level limit that protects the pump.
• Maintain an emergency reserve separately when appropriate.

The estimate supports sizing and refill planning; actual demand should be monitored.