With a cistern filter, you ensure that only cleaned rainwater flows into your water butt. This is generally an advantage, but it is particularly important if you want to use the collected water to flush the toilet or the washing machine, for example. In our guide you will find out what is important when buying a rainwater filter.
If you want to use rainwater for the washing machine or the toilet, you should filter it
Our recommendations
our recommendation
Rainwater filter cistern filter 3P Compact filter K with stainless steel sieve for installation in the cistern, connection DN 100, height offset 0 cm. For using rainwater in the house and for watering the garden
EUR 199.90 To the product| Type | pass-through filter |
|---|---|
| installation location | cistern |
| material housing | PE |
| Material sieve | stainless steel |
| Height difference inlet/outlet | 0 cm |
| connection | DN100 |
The 3P compact filter impresses above all with its flexible applicability. It is the ideal solution when there is little space and no difference in height between the inlet and outlet. The housing made of stable and easy-care plastic and the stainless steel sieve underline the value of the model, which works according to the throughput principle and therefore only rarely needs to be serviced and cleaned. The quality of the 3P compact filter obviously also convinces buyers of this version on Amazon.
our recommendation
Rainwater filter cistern filter 3P Retention and infiltration filter with stainless steel sieve for installation in the cistern, connection DN100. For using rainwater in the house and for watering the garden
EUR 199.90 To the product| Type | basket filter |
|---|---|
| installation location | cistern |
| material housing | PE |
| Material sieve | stainless steel |
| Height difference inlet/outlet | 0 cm |
| connection | DN100 |
In terms of material, exactly the same properties apply to the retention filter from 3P as to the winner in our cistern filter comparison test based on the basic characteristics and the reviews on amazon.de. However, this model acts as a basket filter. This means that the dirt is "trapped" in the filter basket. It is therefore very important to regularly remove the basket and clean it carefully. Amazon customers are positive about the cistern filter. "It does what it's supposed to do," is the basic tenor.
our recommendation
Rainwater filter cistern filter 3P garden filter S with plastic sieve for installation in the cistern or plastic cistern, connection DN100, height offset 0 cm. For rainwater harvesting in the garden
114.90 EUR To the product| Type | basket filter |
|---|---|
| installation location | cistern |
| material housing | PE |
| Material sieve | PE |
| Height difference inlet/outlet | 0 cm |
| connection | DN100 |
And once again 3P: The proven specialist for cistern filters offers the best and a wide selection of designs. With the garden filter, there is also a variant for bargain hunters who want a stable filter at a reasonable price. It works according to the basket filter principle. Last but not least, the screen, which is made of PE like the housing, is responsible for the lower costs. Reviewers write that the filter works well and catches all dirt. An excellent option for beginners!
Purchase Criteria
Type
basket filter: The "entrained" dirt particles from the rainwater are collected in a filter basket. The basket should be cleaned regularly. If you only want to use the collected rainwater from the cistern for watering the garden, a cistern filter with a filter basket is perfectly adequate.
pass-through filter: This variant separates the rainwater from coarse dirt and fine particles in a special way. It directs the water through a filter cartridge that filters the dirt out of the water. While the cleaned rainwater flows into the rain tank, the dirt flows through the ingenious slanting position of the filter or through the extremely smooth surface of the screen fabric and the water that flows on in the direction of the sewage system.
tips
The combination of both techniques increases the filter effect. It is therefore worth looking out for models that are, so to speak, doubly equipped.
place of installation
Cistern filters also differ in the installation location. There are models that you place in the downpipe, versions that you attach in front of the water butt (as earth filters that are installed above the tank in underground cisterns), and rainwater filters that you mount directly in the cistern ("real" cistern filters). . Each of these variants can make sense. The most important thing is that you can easily access the cistern filter - for maintenance and cleaning.
material
The housing of a cistern filter is usually made of plastic. This is quite practical, because if processed well, PP, PE and Co. prove to be durable and easy to care for. The filter basket or the filter cartridge should be made of an extra robust and rustproof material - ideally made of stainless steel. Cheaper models have a screen that is also made of plastic.
resilience
Whether positioned on the downpipe, in the ground or in the rain barrel: the cistern filter should definitely have a high load capacity. Especially with earth filters you have to check whether they can be driven on or at least walked on. Of course, the material of the filter also plays an important role here. The more robust it is, the more resilient the entire device is.
frost resistance: If you want to install the cistern filter underground, the frost resistance does not play a decisive role, because it is always a little warmer in the ground. On the other hand, if you want to use the rainwater filter on a downpipe, even during the cool winter months, it must logically be frost-resistant.
maintenance and cleaning costs
Maintenance and cleaning should be kept to a minimum. Fortunately, this is the case with most modern designs. For easy cleaning, the filter medium must be easy to remove. To determine whether your targeted rainwater filter meets this criterion, you should read customer reviews and authentic test reports. The basic rule is: Earth filters are definitely the quickest and easiest way to get at them.
Height difference between inlet and outlet
If you retrofit the cistern filter, you must also take into account the height difference between the inlet and outlet.
youtubefrequently asked Questions
What is a cistern filter?
A cistern filter, also known as a rainwater filter or pre-filter, is a special filter element. The filter serves to clean rainwater before it enters the cistern. He acts as the first of several cleaning stages. Depending on what the collected rainwater is ultimately to be used for, there are different filter models.
Why do you need a cistern filter anyway?
A legitimate question, because rainwater is actually clean enough to be used as service water (e.g. for flushing toilets or washing machines) without hesitation. However, it often washes leaves and other plant parts as well as dust, other dirt particles or insects along with it on the way into the rain barrel. A cistern filter makes the water as pure as it originally fell from the sky.
How does a cistern filter work?
The rainwater is fed into the cistern filter and cleaned via the integrated filter basket or filter cartridge. In the case of a basket, the dirt stays inside until manually removed by the gardener. With a filter cartridge, it works like this: The cleaned water flows into the cistern, which acts as a rain collector; the dirt load, on the other hand, is reliably flushed into the sewage system by a clever filter design and the water that flows in afterwards.
How do I properly clean a cistern filter?
Some cistern filters are equipped with a so-called backwash device. In this case, you can conveniently carry out the cleaning over it. Otherwise, remove the filter inserts and clean them as recommended by the manufacturer in the instructions. We advise you to clean the cistern filter at least every two to four months in order to constantly maintain the high functionality of the utensil.
Which brands offer good cistern filters?
The 3P brand is a specialist in high-quality cistern filters. Well-known and popular manufacturers are also Intewa and Wisy Linear.
Where is the best place to buy a cistern filter?
Cistern filters are available in well-stocked hardware stores and garden centers. However, the selection at OBI, toom, Bauhaus, hagebaumarkt, Hornbach, Dehner and Co. is generally not as large as at Amazon. The popular online mail order company also offers you a convenient ordering and return procedure.
How much does a cistern filter cost?
You usually pay between 100 and 300 euros for a high-quality cistern filter. Accordingly, the purchase is quite expensive, which is why you should make your selection carefully. Especially if you want to use the collected rainwater not only for your plants, but also for yourself in the house, we advise you to buy a first-class rainwater filter.