RV Antifreeze – any of several brands. We usually purchase it at a local general retailer or auto supply store. Here’s another article with some good information.
Here’s a good video from Travels with Delaney on the process.
It’s important to protect your trailer’s plumbing lines and valves before freezing weather hits. After draining all the tanks, we use the RV antifreeze to protect the pump, tank valves, and traps. We do use vodka in the fresh water tank. We got that idea from Mandy Lea.
Five Star Saniclean from Amazon or from a home brewing supply store.
Here’s Travels with Delaney on dewinterizing their T@B 400 using bleach:
With model year 2021, nüCamp began using a Nautilus System. Here’s an excerpt from the T@B Forum on how to to De-Winterize with the Nautilus:
We use Five Star Saniclean (10 ounces in our 30 gallon tank) instead of bleach to sanitize our fresh water tank and lines in the spring. The procedure is the same as with bleach but requires only a minimum of three minutes before draining the tank and refilling with fresh water. We first learned about it in a thread on the T@B Forum and since it has become our preferred method.