Yes, I fitted a similar system a few weeks back... in fact, I went a step further and also got a de-ionisation (DI) stage which takes the water right down to a big fat 0.000 on my TDS meter. My motivation was that I live in whatI perceived to be a very hard water area (St Albans): our showers certainly coke up faster than
Mother Shipton's cave.
Well I can say it's a very neat system and it works a treat. HOWEVER you may be interested to hear that I'm planning not to use it for my next brew...
First of all, it works absolutely perfectly. As you say, it's pretty slow - about 6 litres per hour - but that's not a problem so long as you don't mind collecting your water the day before you intend to brew. One other thing to be aware of, mind, is that it produces quite a lot of 'waste' water: part of the process is that it produces about three times as much 'black' water as pure. Again nothing wrong with that; the whole process altogether probably uses about the same as a couple of baths-full, and the 'black' water (actually it's just very slightly more minerally) needn't go waste if you can use it for irrigation or whatever.
Also I have been very pleased with the beer that this water has made. I've added some minerals back into it (a little Epsom salts and a little table salt) to give the yeast something to 'chew' on, but the fermentations (with Safale S04) have gone like a train and cleared down beautifully. My only caveat has been that from a subjective point of view the beers (all-grain hoppy English Pale Ale) have seemed a bit lacking in body and character. Not problematically, but something I want to work on. And after due consultation, I've been advised by a few people here that the very pure water might be a part of the issue (probably the yeast too, but that's a different story).
Anyhow to cut a long story short, I bit the bullet and started reading up about water chemistry and talking to a few knowledgable and helpful people on the forum (step forward and take a bow,
@strange-steve and others). My initial objective in that was to work out how better to 'fine tune' what I was adding to my RO+DI water to make the 'best' profile for the style of ales I want to brew. However the more I learned and listened, the more they convinced me that it makes far more sense (and it's easier!) to just start with the water I've got, and adapt that. In fact, my water's fine: it just has a bit too much alkalinity.
So in summary - yes it's a great system (I do actually use it for rinsing off the car and washing the windows) but you
probably don't need it for brewing... the risk is, you take out a lot of trace elements that are actually useful to the yeast and add character to your beer.
) Camden tabs also remove chloramine...
