The 10 gallon is larger, with a need for more space - probably not included in the original design. Wider and taller.
The 6 gallon tank is very hot - normally around 140F. That is enough to mix 1:1 with 60F incoming water to give a 12 gallon shower around 100F. Because it is "Camping" some sacrifice is to take a shorter shower, afterall the fresh water tank is only 60 gallons - give or take. The grey tank probably smaller than that. Most shower heads only allow about 1.5 gallons per minute flow, and most water pumps are likewise limited to about 1.8 or 2.5 gallons per minute.
If they can take a "Navy shower" - that is soap up, then shut off the water while washing, then rinse fairly quickly, they can use the shower and use less than 5 gallons of water total. In a campground, they can use more water, with full hookups, but still they should conserve. It is camping!
When I was living in my RV, and it was 40F out, my incoming water was also 40F, so my 6 gallon water tank was only lasting me about 5 minutes! A very short shower indeed, and I had put in a hard day's work too. So what I did was fill the fresh water tank with warm water, and that 80F water mixed with 140F 6 gallons of water let me take 10 - 15 minute showers without conserving at all!
If your outside shower hose will reach the fresh water inlet, you could fill it with some of the 140F water, and thus fill that tank with warm water. 10 gallons of 140F water will change a 50 gallon water tank from 60F to about 15F warmer.
Good luck!
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a
Porsche or Country Coach!
If there's a WILL, I want to be in it!
I havn't been everywhere, but it's on my list.
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