KLARO Retrofit kit

We call the components in the sewage tank a retrofit kit. It is put together individually for each project and can be adapted to a wide range of tank types and sizes.

KLARO uses only high-quality and robust built-in parts. All components are either made of wastewater-resistant plastic or stainless steel. The concept is based on the KLARO principle:

NO mechanics - NO pumps - NO electrical parts in the wastewater.

This makes the technology particularly reliable and durable.

These advantages make the KLARO retrofit kit special:

  • Adaptable to new and old containers of all types, whether concrete, plastic or GFK containers
  • Compatible with almost all pit geometries
  • Easy to mount
  • High quality and durable components
  • Trouble-free operation
  • Pump processes via air pressure lifter
  • Oxygen input via membrane aerator
  • Effective and economical operation

Air lifter

At KLARO, all pumping processes of water and sludge are not carried out by submersible pumps but by air-lift pumps. In addition to water and larger solids, these pumps can pump water and sludge without any problems or wear. The mode of operation is based on the "mammoth pump principle". The compressed air required comes from an air compressor, which is located in the switch cabinet outside the container. The lifters themselves are designed in such a way that an optimum conveying behaviour is achieved by clever selection of cross-section, length and blowing air quantity.

At KLARO we distinguish between three types of lifters:

  • Charging air lifter
  • Drain lifter (or clear water lifter)
  • Excess sludge lifter (or return lifter)

Special features of KLARO airlifters:

  • No suction of floating sludge possible
  • A desired minimum water level in the septic tank is guaranteed by design, without the need for a float switch
  • Discharge lifter with patented air barrier to prevent unwanted discharge of activated sludge
  • All lifters color coded
  • Unique siphon series KLARO airlift.blue for smaller systems up to 20 PE


  • Trouble-free and wear-free
  • Patented air barrier
  • Simple and effective
  • Robust and durable
  • Flexibly adaptable - even retrospectively on the construction site
  • Easy mounting
  • No wearing parts
  • No submersible pumps

airlift.blue and Quick carrier system

The airlift.blue air lifters were developed especially for small systems up to 20 PE. They are manufactured in three different sizes from HDPE by blow moulding and are therefore extremely robust. The lifters are particularly suitable for attachment to our carrier system KLARO-Quick and can therefore be easily placed on the partition wall. Later removal for inspection purposes is also possible. The carriers are available for different wall widths up to 14 cm. Alternatively, individual mounting of the lifters on the container walls is also possible.

Special features of the airlift.blue are:

  • High-quality KLARO design
  • All air flows above the waterline
  • All air connections colour coded
  • No breaking of air connections, even at low temperatures
  • Pipe ends (socket and spigot) compatible with standard PVC-HT-DN50 fittings
  • Very good conveying behaviour due to optimum ratio of injection depth to conveying height
  • Extension of the drain lifter up to 60 cm possible
  • Air barrier or inlet baffle to prevent the discharge of suspended matter


  • Air connections on the top
  • Patented air connections
  • Particularly robust
  • Particularly easy installation

Aeration unit

The aeration system is one of the most important components in a sewage treatment plant. It must be reliable and as fine-bubbled as possible. This is why KLARO does not use surface aerators with propellers, but membrane aerators with compressed air at the bottom of the tank. The air blown in is required by the microorganisms for the degradation processes and is also used to circulate the activated sludge. KLARO works exclusively with high-quality, low-softener membrane aerators made of EPDM.

Depending on the type and size of the plant, different aerator units are used, e.g. disc or tube aerators. There are weighted aerators which stand individually at the bottom of the tank or air distribution systems made of robust stainless steel to which the aerators are screwed.


  • Fine bubble ventilation
  • Especially effective and durable
  • Energy efficiency
  • Easy to install
  • No mechanical or electrical parts in waste water
  • Adaptable to any pit geometry and container material

Sampling Point


  • The drain lifter transports into the sampling point
  • At each discharge process, old water is displaced and fresh treated wastewater remains
  • Different sizes depending on the lifting dimension
  • Possible pipe connections DN 100 and DN 150
  • With emergency overflow


  • Sequence samples can be taken at any time, no matter what phase the plant is in
  • Sufficient volume available
  • Grey colour for easy identification of water quality

Air Hoses


  • For connecting the set-up kit and the control cabinet
  • Made of fabric-reinforced PVC
  • In different colours
  • Up to 25 metres in length
  • Available in 13 mm, 19 mm and 25 mm diameter



  • High quality material
  • Robust and durable
  • Colour coordination makes for easy installation

Empty tube plug


  • For sealing the empty conduit between the line and the control cabinet
  • Recesses in the appropriate sizes for the hoses to be fed through
  • Made of PE foam
  • For pipe cross section DN100


  • Clean and professional finish
  • Easy to install
  • Retrievable

Success can be measured

KLARO in numbers
- You can count on us.


Users worldwide


In over 80 countries


Specialists in Bayreuth