Here is how I did mine, in a sink. Most of these portable RO units come with fitting to fit up to faucets. I would just caution you to set it up in a way that it doesn't flood your basement if you forget about it or parts fail or whatever. The ones with pressure tanks aren't as portable but are more automatic. I set this one up with a garden hose timer so I can set-it and forget-it. Before I bought the timer, I had forgotten about it a couple of times and it ran all night, overflowing into the sink and into the septic system. Its not a huge amount of water but still not good.