Well, first off I'm alone aboard, so don't use much energy. The AGM battery bank is 1000 AH (at 24V).
If I'm doing the math correctly, that's 2000ah at 12v. Wow!! That makes a big difference. I feel better about why my 400ah needs daily recharge.
The quiet and energy efficient Spectra Newport 400 makes about 1 liter per minute. And yes, watermakers want to be run often so that the membranes never get a chance to get biologically active and clogged. Unfortunately the rinse cycle after running uses about 10 liters, so the first 10 minutes of running the watermaker are just producing the water subsequently needed to clean the unit; for me 1 hour is about the minimum I'll run the system, giving me only 1/5 wastage.
This is an important concept for the OP to understand. That is a net of about 13 gallons for one hour of running. That's around the minimum per person comfortable "marine" usage, ie basic conservation, no wasted usage. Of course, you can keep usage substantially lower if one chooses, but add people and you would add hours of running the watermaker. One could get a bigger one than the 400, but that would be expensive and likely too big to find a place to install on most boats.
Also worth pointing out that you need to draw relatively clean water to make water. Inside harbors with potential organic or chemical contaminants can be hard on a watermaker (depends on the harbor).
I do make sure that I get lots of "mineralised water" as well and usually get it in the form of "Caribe" or "Presidente" or "Red Stripe" in conveniently sized packages.
Now that's some good advice.