[mark]

Okay, you're talking the supply to the ro/di, for some reason I thought the faucet Aquasafe has for the output.

Usually a bathroom or kitchen faucet has a screen secured with a screw in collar. If you can get the collar off then there's adapters that go on the fine threads on the faucet then allow a garden hose to be screwed on (old water bed days) or other pipe threads.

If that doesn't work, under the counter tee into the cold water line after the shutoff valve and before the tap-set. Between the tee and the ro/di put a valve in so you can remove the unit. Might even be better this way as not tying up the sink in the bathroom or kitchen if making up water.