ᐅ Plastic Cistern vs. Concrete Cistern for a Spring Project

Hello dear forum members,

I hope you are all enjoying the first signs of spring as much as we are! With the changing weather, we have decided to put a long-held plan into action – installing a rainwater cistern in our garden. Our goal is to become more independent and to save water and money in the long run.

However, we are now facing a decision where we rely on your experience and advice: should we choose a plastic or concrete cistern?

On one hand, we often hear that plastic cisterns are easier to handle and install. On the other hand, we have read that concrete cisterns can apparently be more durable. Since we are planning to connect the cistern to the household water system (toilet flush, washing machine) in the future, we are unsure which type would better suit our needs.

Has anyone had experience with both materials? What advantages and disadvantages have you noticed?
We would really appreciate your opinions, tips, and recommendations to make the right choice for our spring project.

Thank you in advance!
SusannNisch

Hello Susann,

I would like to share my experience on your topic. I chose plastic, even though I do recognize some advantages of concrete. However, in the end, the arguments in favor of plastic convinced us.

A major benefit was the lighter weight of plastic cisterns compared to concrete ones. This not only made transportation easier but also significantly simplified our do-it-yourself installation. As a result, we were able to save substantial costs both on purchasing and installation.

Another important factor is the durability of plastic. Modern plastic materials are resistant to corrosion and weather conditions, which significantly extends their lifespan. According to the manufacturer, the plastic of our cistern is even food-grade and comes with a 25-year warranty. While concrete is known to be sturdy, it can develop cracks over time and may be more vulnerable to environmental influences.

Good luck with your project!

The decision should also depend on the soil type.
If it is sandy soil, then plastic or concrete.
If it is clay soil with poor drainage, then concrete,
as plastic could float.

SusannNisch schrieb:

Since we are planning for the long term to connect the cistern to the house supply (toilet flushing, washing machine),

Regardless of the pros and cons of the materials used (both work well, with different costs, ground conditions, DIY versus professional work, etc.), a note that you must have a separate pipe system for the toilet flushing and similar uses. The water must never come into contact with the public water supply. This could be an additional factor leading to high costs if nothing has been prepared in advance.

Finally, I would suggest considering the option of a well. This depends on the groundwater level—if feasible, it is usually the cheaper alternative and, especially after the recent hot summers, could be the more practical choice for irrigating the garden during peak season.

Nida35a schrieb:

The choice should also depend on the soil type.
If it’s sandy soil, then plastic or concrete is suitable.
If it’s clay soil with poor drainage, then concrete is recommended,
as plastic could float.

Concrete tanks can also float if groundwater accumulates. However, they are less at risk because of their heavier weight. For plastic tanks, this issue can be addressed by installing a groundwater valve, which concrete tanks do not have. This works with both groundwater and standing water. Make sure to consider this when purchasing!

Nida35a schrieb:

The choice should also depend on the soil type.
If it’s sandy soil, then plastic or concrete is suitable.
If it’s clay soil with poor drainage, then concrete is recommended,
as plastic could float.

Hello everyone,

that is not entirely accurate. Concrete tanks can also float when groundwater builds up. However, they are somewhat less vulnerable due to their greater weight. This problem can be solved for plastic tanks by using a groundwater valve. It works with both groundwater and standing water. Be sure to keep this in mind when buying—a floating tank usually means it is a total loss. The risk is not worth it and can be eliminated by installing the groundwater valve.

Lunkomen schrieb:

Concrete cisterns can also float when groundwater rises. However, they are less at risk due to their heavy weight. Plastic cisterns can address this issue with a groundwater valve, which concrete cisterns do not have. This works for both groundwater and standing water. Definitely keep this in mind when purchasing!

Hello everyone,

that is not entirely accurate. Concrete cisterns can indeed float when groundwater raises. However, they are somewhat less vulnerable because of their greater weight. The problem can be solved with plastic cisterns by using a groundwater valve. This works in both groundwater and standing water situations. Make sure to consider this when buying, as a floating cistern means total loss – the risk is not worth it and can be eliminated with a groundwater valve.

I also have the groundwater module or groundwater valve and am very glad I do. I have seen a tank nearby that slightly floated up. Nothing happened with mine! I only know of one manufacturer offering this solution.