This product seems to have all the guarantees of conformity and is certainly not an against-how, contrary to what is said in another comment. A sealed capsule closes the opening in addition to the cap. I bought it after I inquired on Amazon UK for the British flag is seen on the bottle. Opinions were all very positive about its effectiveness and Lampco seems a respectable distributor. It is likely that if color differences there, they are due to differences in composition between the UK and France Version (maybe environmental standards issues). My installation is deemed PEX pipes to let the air filter causing bacterial sludge, which was added home magnetite. All caused me clogged circuits and désembouages that discouraged even professional (I had to finish only). I put 2 liters of X400 in my setup that requires in 1.5 L. After 3 months I really have no problem circulating water as I had before, but the water remains blackish. The manufacturer does not prohibit overdose or limitation in time, I decided to let the product continuously and now put it to the annual maintenance, rather than the X100 which seems less powerful.
