installing my APEC ROES-50, can I drill through granite for the faucet? what size bit?

You can drill granite, but you need the right tools and patience. The hole size depends entirely on which faucet you're using.

1. For the standard faucet included in the kit, you need a 1/2" drill bit.
2. If you have an air-gap faucet (often required by code to prevent back-siphonage), you need a larger 1 1/4" hole.
3. Use a variable speed drill. For granite, start with a small pilot hole (a 1/8" bit is recommended) to guide the larger bit. Use water to keep the bit cool and lubricated while drilling.

If that didn't work: If you're not comfortable drilling stone, consider installing the faucet in an existing hole (like a spare soap dispenser hole) or use a countertop mounting plate designed for RO faucets.

Heads up: Always follow local plumbing codes for installation. The air-gap faucet is specifically for areas that mandate an air gap. The drain saddle must also be securely attached to your sink's drain pipe, not the garbage disposal.