I have long favorable Tabs of DM, Rewe, Lidl, Aldi, among others ,. used. Over the last 10 years there have been different. Side effects with it, such as glass corrosion (milky glass surface which is impossible to remove) and especially last white, extremely greasy fat-liquor residue in the sieve of the dishwasher which the rinsing significantly deteriorated and a frequent manual cleaning required. The fat-liquor residues occurred particularly with the acquisition of a new Siemens dishwasher, as opposed to previous Bauknecht, examined the water on the degree of contamination, thereby reducing water consumption to the absolute minimum the. Obviously now that enough for the cheap Tabs no longer sufficient to flush the fat of bound residues with out of the machine. After these residues were repeatedly, I have ultimately times the Somat-Tabs tried again after years and after 3 washes the residues were gone and have since no longer occurred. See also the glasses (which do not yet have glass corrosion - existing glass corrosion eliminate namely the Somat-Tabs not) far better than with the low-Tabs. I'm sorry for the trouble and buy now only practical Somat Giant Pack at Amazon.
Update Jan / 2015: After several attempts with the Somat 7-Tabs I now make this one, because the result so with me worse or markedly different is not, at the same price but a good 22% more content in it.