Water Hose Sizes

I am re-plumbing my new to me system and one of the things I am addressing is the supply from the house to the tank. I found this and thought it might be helpful because it addresses flow rates adjusted for hose lengths. It would appear that if your running more than 100’ of garden hose you really need to consider going to 3/4" to try to keep up with the higher GPM machines.

“Differing Lengths
Both 5/8- and 3/4-inch hoses come in various lengths. From 25 to 100 feet long, choose the best length for your property. Be aware that a longer hose reduces the water volume expelled. For example, a 5/8-inch hose 25 feet long produces 44 gallons per minute (gpm). The same diameter hose at 100 feet long has a much smaller output at 11 gpm. Because 3/4-inch hoses have a wider mouth, their output for a 100-foot hose is slightly larger at 18 gpm, but the 25-foot hose increases the water flow to a staggering 72 gpm.”

I am new plumbing a new trailer as well. I am using 5/8" supply hose. The pump for this trailer will be 8 gpm. So I incorporated an 125 gallon buffer tank with 1 1/2" supply going out to pump inlet. First order of business at the job site is supply line hookup to allow tank time to fill a reasonable amount, while setting up lines and equipment.

Roger that. There have been number of threads relating to upgrading to the 3/4" flexzilla for example and I have been wondering what if any benefit there was based on using a buffer tank. I noticed that justrunning my 8 GPM ( I have a 6 GPM too both plumbed to a 325 gal tank) that I was going backward off the buffer tank at a pretty good rate so I started looking at the buffer tank replacement rate. That’s what led me to doing this post since the flow rates were empirical rather than perception based. I sometimes have to run over a 100 ft of garden hose so for me it means I am going to a 3/4".


I have a 3/4 inch hose and a Steel Eagle reel with 3/4 internal plumbing. Make sure if you run your supply hose through your reel you have the larger diameter internal parts to match or your wasting your time.

You can never tell what supply will be available at the site. Some homes may have 3/4" mains and 1/2" hose bib supply at a lower than optimum pressure. All you can do is hope your supply lines are not the bottleneck. I chose the 5/8" supply based on the lighter weight and can mount a little more on the reel. I originally plan to not use the reel swivel and direct to fill bulkhead with the hose. Time will tell. Your 325 tank should provide a sufficient supply, but it may fill slowly depending on the site supply, obviously. In my area, residential pressure is plenty! And most have 1" mains, but you never know.

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That’s an excellent point. My reels are 3/4" too.

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