ispring rcc7ak-bn leaking at the tubing connection, how do i fix it?

That's almost always because the tube isn't seated all the way into the quick-connect fitting. You need to create a seal past the internal O-ring.

1. First, remove the blue lock clip from the fitting with your nail.
2. Check if the tube has a clean, square cut. If it's ragged, trim it with scissors or a utility knife.
3. Mark 5/8" from the end of the tube. This is your insertion depth target.
4. Push the tube into the fitting until you feel resistance at the O-ring. You'll need to wiggle it and apply firm pressure to push past it. Keep going until your 5/8" mark is at the fitting's edge.
5. Once it's fully in, pop the blue lock clip back on to lock it.

If it still leaks after that, the O-ring inside the fitting might be damaged or kinked. Unscrew that elbow fitting and replace it with one of the spares included in the kit. Wrap the threads of the new fitting with Teflon tape before screwing it back in.

Check for leaks daily for the first two weeks and use the included flood alarm.