Originally Posted by NMWildcat
I always buy two 5/8" fresh hoses. That way when I fill my fresh tank I have more flow than the smaller hoses
. And I buy a 50' 5/8" hose for the black flush and draining the gray tank..... Quickly. 🙌
This is a reason to buy the 5/8" hose. You can fill your fresh water tank faster. OTHER than that it doesn't matter what size hose you have. I personally have a PRESSURE regulator attached inside my control panel door at all times. If your supply pressure is lower than what you have your regulator set at it isn't going to change anything 1 iota! BUT if your supply pressure is higher than it is set at it will save you from a catastrophic failure of your piping.
2 different components of water dynamics should NOT be that hard to understand.