This kitchen has an extra faucet. It is smaller than the main faucet.
It appears to bypass both the water heater and water softener. It also appears to not have any aeration (no bubbles even when turned up to full stream)
There is a symbol that looks like a water drop crossed out. Also it appears to have a reservoir because after the faucet is in use for a while (e.g. a cooking pot full) the stream gets weaker and weaker, until it sits for a few hours to fill up again
What is it for and does it have a name? Since it seems to not be softened, how do the pipes leading to it not get corroded?
Location: Chicago, IL on a private well
Here's some pictures under the sink. Actually I don't see anything that resembles a reverse osmosis filter (the red thing is a garbage disposal). But the faucet is an exact match to some GE reverse osmosis faucets, so I guess the filter itself is somewhere else. Next to the sink are a dishwasher and cabinets and there is definitely no filter in them either.