Our kitchen faucet is a Grohe Concetto, single arm, less than a year old, never gave us trouble. A month ago it began leaking into the cabinet below and I figured out that the sprayer hose (which is incorporated into the faucet, so you basically pull it out of the faucet tip) had gotten spun / screwed around a few times, causing water to spring out of it several inches from the tip, which was running down within the fauce along the outside of the hose within the faucet and falling into the cabinet. Obviously I just un-revolved the hose a couple of times and the leak stopped. Now, however, the faucet has noticeably lower pressure and when you turn it off, it stops gradually (1-2 secs) rather than all at once. I've tried twirling the sprayer hose both ways and it doesn't change things. Both of the valves below are all the way open. The sprayer line isn't kinked from what I can tell. The aerator doesn't seem clogged and that would be weirdly coincidental so I don't think it's the case. Help!