Our tanks came with threaded holes to connect plumbing, some of the holes needed to be drilled/opened.
Can you post pictures here of the tank, and any existing holes it may have?
Specifically around fresh tank plumbing:
Note you will want at least, (and probably at most) two holes in the fresh tank- one near the bottom of the water for filling/draining, and one near the top for overflow and for air to escape/enter the tank when it is being filled/drained respectively. The overflow/air hole should go outside so that in the event you overfill the tank the excess has somewhere to go. You do not want shore/city water to be able to pressurize the tank as it could rupture.
More generally around plumbing:
There are some questions about what you hope to accomplish with your plumbing setup. Do you want to:
- Be able to hook up a pressurized hose and bypass your tank altogether, so that while you are hooked up you don't have to worry about how full your tank is (or even have to run your pump for that matter),
or;
- Always run by pumping from your fresh tank, filling via a gravity fed inlet only (not pressurized)?
We tend to "dry camp", as in fill our tanks every X days or so and run off the pump. However, I fill my tanks via a direct hose line (not a gravity fill port), and I did install valves as to allow to bypass the fresh tank, although perhaps due to winter it isn't a feature I've used very much.
If you're interested I can film a video of our fresh water fill routine and explain all of the parts of the plumbing. However I'll warn you, my setup is not perfect and may not be for you!
Best of luck!