I installed Grünbeck softliQ:SC18 as a replacement for GENO-K4. Bought from egshop-ulm on ebay.de for 1479 EUR with a bag of salt included. Later I also bought and installed a special drain connector 188875.

Installation

Installation took 2 hours and minimal amount of tools because both use the same 190mm connector and I didn't have to install the ends.

Installation steps are nicely laid out in the manual.

One curious point is that the service interval is also set during initial installation. I assume that if your installer will set it to 1 year, as recommended in Germany, the device will stop working after that period - but I'm not sure.

Water taste

I'm quite happy with SC18. The water taste did change for the worse due to additional 100mg of Natrium but we got used to it. Any salt-based water softener would do that and SC18 in particular adds 8.2mg/L for every dH removed.

I did a chemical water analysis a few weeks after the installation and didn't see any changes apart from the planned Natrium increase.

Effectiveness

There's a major decrease in mineral deposits everywhere now. Water hardness can be controlled with a mixing valve (small knob in the middle) but I've heard that going below 5 has some risks.

Edge cases

SC18 turned out to not be an all-positive device too: according to the manual "water can flow down the drain uncontrollably if there is a power failure during regeneration" which wouldn't be great since my basement waste water pump also doesn't work without power source. Admittedly, this situation is quite unlikely here in Germany. In 5 years I'm here we haven't had a power outage at home, only in the office for a few hours.

This is one of the reasons they recommend installing an emergency shut-off device but I don't have space on the pipe readily available for it and it's quite expensive. Maybe I'll put together a battery-powered valve-turning contraption one day - as there's already 2 manual valves on the pipe before the SC18.

Size

SC18 is also smaller than GENO-K4. This is actually somewhat problematic because in addition to the pressurized drain line, SC18 has a gravity-fed emergency drain and, naturally, your drain connection has to be lower than 50cm output height.

Hose angles

Another complication with SC18 is the hoses that it comes with. They have straight connectors on both sides but have strict requirements how much you can bend them. In my case I had to offset the device from the wall. Grünbeck appears to sell 90-degree brass angles "Anschlusswinkel 90 °-1 2x MC32 187 865" which can be found for 60-90 EUR. I'm considering getting those.

Salt usage

SC18 uses surprisingly little salt. My neighbor has it for 1.5 years and reports using only 50kg salt per year for a 4-person family. This of course depends on how many degrees of hardness you want to remove and how much time your family members like to spend in the shower. In my case it looks more like I'd need about 100kg per year.

WiFi

SC18 has WiFi functionality but I don't plan to setup that. I can't think of a use case and the security and reliability consequences of this make me feel uneasy.

There's a humongous years-long thread on https://www.haustechnikdialog.de/Forum/t/177415/softliQ-SC18 (in German) which is mostly about WiFi troubles. It's been reported that they are mostly resolved in the new units.

Removing salt from the water

It would be great to restore the original water taste by removing the salt but looks like very few filters can do that and reverse-osmosis is the main option. I'm not sure if I want to install one because:

  • It takes space under the sink
  • Costs 100-200 EUR per cubic meter of pure water
  • Removes other vital minerals from water, some re-add them in the final stage
  • May require power for decent flow or you'd have to fill your kettle a full minute
  • Need maintenance twice a year
  • May need to drill the kitchen counter depending on the setup

I'm leaning towards just running an extra pipe to the kitchen that doesn't go through the softener.

8 months update

I tried to compare the water taste before and after the softener and can no longer tell the difference! So are my family members. Guess we've got used to the increased salt content after all. Overall, the softener is working without issues and we've used up about 3 bags of salt already (each 25kg).