Yes Graf the German water harvesting giant has entered the world of sewage treatment, the question is are they any good?


Graf have two models on the market the Klaro and the One2Clean both models are based around the Graf Carat tank made from HDPE (high density polyurethane)
making these units very sturdy simple to install the differences between the two is that the Klaro has more add on options and comes with more gadgets but both will produce a very good rate of purification.


As stated both these units are very good performers but even tough the One2Clean is the more budget tank of the two it does produce a slightly better rate of waste water purification, here are the figures


COD (chemical oxygen demand)94.2%

BOD (biochemical oxygen demand) 98.0%

SS (suspended solids)96.3%

NH4-N 98.3%

N total 87%


COD (chemical oxygen demand)91.9%

BOD (biochemical oxygen demand) 95.9%

SS (suspended solids)94.4%

NH4-N 65.4%

N total 57.1%

Results of practical testing undertaken by the Prüfinstitut für Abwassertechnik (Testing Institute for Wastewater Technology), Aachen

Also both these units pride themselves in their energy consumption that is lower than a energy saving bulb only using around 43kwh

Ease of Installation

The Carat S tank is exceptionally easy to install due to it being completely groundwater safe even with a granular install this means you can not only save a lot of money on concrete but have peace of mind that the tank won’t be popping out of the ground.

Both the Klaro and One2Clean can also be installed in a driveway with the optional vehicle loading cover.

The electrical installation is very simple also as all the moving parts can be mounted indoor ind then just plugged in to the nearest plug socket.


These wastewater treatment plants are versatile and very good value for money if you are on a budget the One2Clean is a fantastic option at it doesn’t compromise quality even at a low price point or if you are after something a bit more singing and dancing the Klaro won’t disappoint.

Please visit the shop for prices: