The old plastic plumbing from the water tank to the faucet can be pretty gross and even black with bacteria. It’s a good idea to replace it if it looks at all suspicious.
Here are some step by step instructions on replacing the plumbing. These instructions also include setting up the GoWesty Pump Faucet. We have used both the pump sink and the Shurflo Electric Faucet. Buy the Shurflo!!!!!