What hose do I need to empty a tank or cistern?

Emptying a tank or cistern is a common task in rural homes, gardens, farms and systems water storage. However, one of the most common questions is Which hose do I need to properly empty a tank ?

Choosing the wrong hose can lead to slow draining, blockages, leaks, or even damage to the equipment. This guide explains which hose to use depending on the type of tank , if you need pump or not, and how to do it safely and efficiently.

Index

1. Types of tanks and cisterns
2. Methods for emptying a tank
3. Emptying a tank without a pump
4. Emptying a tank with a pump
5. Which hose to use in each case
6. Recommended diameter and length
7. Common mistakes
8. Conclusion

Types of tanks and cisterns

Before choosing the hose, it is important to identify the type of tank you want to empty:

• Elevated tanks: allow emptying by gravity.
• Ground level tanks: may require a pump.
• Underground cisterns: they usually need a pump.
• Drums or vats: small volume, simple method.

The height of the tank and the location of the outlet point determine the appropriate method and hose.

Methods for emptying a tank

There are two main methods for emptying a tank or cistern:

1. Empty with a hose without a pump (siphon effect).
2. Empty with a hose using a pump .

Emptying a tank without a pump (siphon effect)

This method is only possible when the starting point is lower than the level from the water in the tank.

When is it advisable

• High deposits.
• Drums or vats.
• Occasional emptyings.
• Clean water.

Which hose to use

• Flat hose: lightweight, easy to use and with good flow rate.
• Traditional flexible hose (if not kinked).

👉 To see the process explained step by step, we recommend: How to get water with a hose without a pump .

Emptying a tank with a pump

When there is insufficient slope or the tank is buried, it is necessary to use a water pump .

When to use a pump

• Buried cisterns.
• Ground level tanks.
• Fast draining.
• Water with debris or sediment.

Standard configuration

• Submersible or surface pump.
• Suitable hose for pumping.
• Connectors and clamps securely fastened.

Which hose to use in each case

Flat hose

• Ideal for water outlet.
• Good flow.
• Easy to store.
• Suitable for siphon or pump.

👉 If you want to better understand how it works: How a flat hose works .

Suction hose

• More rigid.
• Resists the pump's suction.
• Recommended for water with residue.

Recommended diameter and length

Choosing the correct diameter is key to efficient emptying:

• Small diameters: drums and small tanks.
• Average diameters: domestic tanks.
• Large diameters: cisterns and large volumes.

Regarding length, always choose an extra margin to avoid unnecessary tension or splices.

Common mistakes when emptying tanks

• Using hoses that are too thin.
• Not securing the connections properly.
• Try to empty without slope or pump.
• Not controlling the process.

Conclusion

To empty a tank or cistern efficiently and safely, it is essential Choose the appropriate hose according to the draining method and the type of installation.

In most cases, a quality flat hose is the most practical option. combined with a pump when there is no difference in level.