Selecting the appropriate rainwater tank depends on several key factors, such as roof area, rainfall in the region, and the planned use of the collected water.

1. Determining tank capacity

The most important factor is choosing the right capacity so that the tank is neither too small (frequent overflow) nor too large (underutilization).

Approximate formula for capacity selection:

$$C=A\times R\times 0.8$$

Where:

C – tank capacity (liters)

A – roof area (m²)

R – average annual rainfall in the region (mm)

0.8 – coefficient accounting for losses (evaporation, splash)

Example:
If the roof has an area of 100 m², and the average rainfall is 600 mm per year, then:

100×600×0.8=48,000L(48m³peryear)100×600×0.8=48,000L(48m3peryear)

If you want to store water for a month, choose a tank with a capacity of about 4 m³ (4,000 L).

2. Type of tank

📌 Above-ground – cheaper and easy to install, but more exposed to contaminants and weather conditions.
📌 Underground – don’t take up space on the property, more resistant to temperature changes, but require excavation work.

3. Tank material

✔ Plastic (PE, PP) – lightweight, easy to install, corrosion-resistant.
✔ Concrete – durable, good at stabilizing water temperature, but heavy and requiring specialized installation.
✔ Steel – less common, more for industrial purposes.

4. Intended use of rainwater

💧 For garden watering – a 2–5 m³ tank is sufficient.
🚿 For toilet flushing and laundry – it’s worth choosing 5–10 m³.
🏠 For full household use – recommended minimum of 10 m³.

5. Additional equipment

✔ Pre-filters – prevent leaves and debris from entering.
✔ Pump – necessary if water is to be used in household installations.
✔ Overflow valve – drains excess water.
✔ Water level sensors – for monitoring the amount of collected water.

Summary

🔹 Small garden → tank 2–3 m³
🔹 Large garden → tank 5–10 m³
🔹 House with rainwater system → tank 10–15 m³

Have you already determined the purpose of water use and the conditions on your property? I’d be happy to help you choose the best solution! 😊
We will answer each of these questions at tel.: (+48) 664 101 600