PSQL Port Collision

I'm trying to run a rails project with psql on port 5432. When I run the rails server I get an error that the port is already in use. I use lsof -i :5432 and I get this:

postgres 83 postgres 4u IPv6 0x7692574bf6fbcbe9 0t0 TCP *:postgresql (LISTEN)

postgres 83 postgres 5u IPv4 0x7692574bf6fc2d69 0t0 TCP *:postgresql (LISTEN)

So I run sudo kill -9 on the PID, however when I go to run the server again I am still getting the same error. This happens when I try to run any psql process. Am I not closing the port correctly or am I missing some step?