Start out with the default setting (3?), and see if you get good results; eg., no spotting, no rinse aid residue (soapy taste on your dishes and glasses), drying ability, etc. You can play with the rinse aid setting if results aren't to your liking (adjust it up or down until you get the desired results). At one point Miele service had increased the setting on ours, finding that some of his customers felt the dishes came out drier, however, we felt it left our glasses tasting soapy so adjusted the setting back to the default. While troubleshooting an issue last year, he suggested trying a lower rinse aid setting (given the rinse aid in the tablet, though we tend to use the Miele tablets cut in half). We ended up adjusting it back up to the default again, as our glassware was too spotty with the lower setting. We always use salt in our machine (Somat or Miele). I think the tech had set our DW to soften the water when it reaches 6 grains of hardness or above. We have moderately hard water, and only need to add salt about once a year or so.

We bought Subzero, refrigerator and freezer, a large Wolf gas range and we got pushed into buying a Cove dishwasher. What a mistake. After 32 days, the dishwasher failed simply saying call service. We are in West Los Angeles, and there is only one company that does warranty work on Cove dishwashers, Box Appliance Repair. We waited two weeks for the first appointment and were told that we needed a new wash pump and it would take a week or two to get it and then they could schedule a follow up appointment. We pressured Cove and they expedited getting the pump so we only had to wait an additional 2 1/2 weeks. Today the technician replaced the wash palm and found that we also bad electronics. He replaced two circuit boards and found that a mechanical relay was also defective. We are now being told that once they get the mechanical relay they will schedule an appointment, probably two weeks away. So, all told we got 32 washes in before multiple parts failed. I told a friend of mine that I bought a Cove and he just started laughing. We have calls and emails into Cove now asking them to replace the dishwasher or give us our money back. I will post the outcome once this dishwashing nightmare is over.

Though it wasn't for a Miele dishwasher, I bought the Miele ultra tabs once out of curiosity (I'm a fan of the brand and they had good reviews), and the oversudsing is a serious issue. This was in my last house with average-to-slightly-hard water and a GE Profile dishwasher. I ran it with a full tab and you could hear the machine straining because it was sucking up so much air from the soap suds. It sounded so bad that I was afraid the machine would be damaged. I opened the door and the bottom was all white foam. Cutting them in half helped, and they got the dishes very clean, without any pre-rinsing. However, I never bought, nor will buy, them again. Considering the high price, the fact that I had to perform labor to make it work properly, and the excellent performance I've gotten with Cascade Complete or Kirkland Signature (without extra work and for far less money), the Miele tabs lost their appeal. I also experienced similar oversudsing issues with Cascade Platinum and the latest version of Finish Quantum, so I stick to the aforementioned Complete or KS.

Posting a follow up to my own question for the benefit of anyone who stumbles across this in the future. The Miele app instructed me to reference the manual. The manual instructed me to shut off the water supply and call Miele, Miele support immediately tried to get me to schedule a paid service call. When I asked if there was any troubleshooting I could do, they sent me this link: http://www1.miele.de/iinet/us/callassistance/sa/ca_3387.aspx Following the steps on that page and this Miele video, I was able to fix it myself without any difficulty. And if I still had a problem, before scheduling a service call I would have followed this additional advice made by a user in the comments: Thanks for the useful video. However, when I followed the procedure I found nothing that would have triggered the F11 error, so I suspected blockage in the drain hose under the sink. I removed the drain hose from the garbage disposal unit under the sink to see if the problem was there. It is easy: it is held on by a hose clamp that you can remove with an ordinary philips screwdriver. The hose was backed up at the end for about two inches with pieces of vegetables. There was blockage at the drain port on the garbage disposal which I poked all the way into the disposal unit with a stick. There was also blockage at the end of the drain hose, which I removed by bending a piece of wire into a J-shape and scooping it out. The rest of the hose was clear. So first follow the advice in this excellent video (which you should do periodically anyway) but also disconnect the drain hose from the garbage disposal to see if it is blocked there. I don't know why Miele wouldn't start with this troubleshooting guide instead of putting customers through the inconvenience and expense of a service call, but this did the trick for me and I'd recommend you try this before calling for help. It was rather simple and no tools or special DIY skills are needed.