I had a six gallon and there was noooooowaaayyyyy we could go back to back to back with showers.Unless you are just putting water on yourself shutting it off soaping up and turning it back on to rinse...My wife and kids are not going to shower like that.So we would have to space them out.But on our new camper we have a ten gallon and we can all go in a row without shutting the shower head off.No one honestly likes to shower turning it on and off.But you can def just use both elec and propane to reduce the time between showers with a six gallon.