Sizing an rv pump for rain collection

[nathan.principe]

its been a couple years since I've posted or even been active in this site.  I have a project tittled 17x24 east tx cabin buried in the owner builder section.  I stopped short of finishing the bathroom at that time and now plan on picking back up.  I opted not to pay for city water and have recently been successful at adding a 300gal rain harvesting system!  I am proud to say after just the first rain it is holding over 100gal!

Now, my question is when choosing an rv pump to supply the water to my supply lines (already installed), what gpm size should I opt for?  It's seems in my short research 3gpm is pretty standard.  Because I know your already wondering I will have 2 sinks, 1 toilet, and a shower all running from the pump ( most likely never at the same time) and all fixture will be with in 12' or closer to the pump, and it the pump will sit at finished floor level in the cabin with only 24" vertical rise from the rain barrel outlet.

Does anyone have any personal experience with this? Or own an rv and know what size pump you used???

Thx in advance!

[MountainDon]

3 gpm is what we have. It works for us. Depends some on how disciplined everyone is about water use.

[rick91351]

Basically with an  RV you have pretty much what you are looking at.  Up side - down side with an RV you are pluged in and hooked up most the time you are really using it. But when you have to or want to 'Boondock it' it is surprising how functional it all is.  3 GPM works just fine.  In fact I think our hot water heater works better with the 3 GPM when we are grabbing a shower than hooked up to a well or a municipal water system.     

[nathan.principe]

Thanks everyone! I'll be sure to post when I have my project conplete

[Dave Sparks]

My advice is take a 3 gpm pump like a shureflo and remove the pressure switch, buy a Square D pressure switch, set it to the spec of the pump and use as big of a pressure tank as you can. A 20 gallon may be hard to fit but 20 to 50 + gallons is what is used in homes.
This will flush toilets and showers all night ( without cycling the pump) to not wake-up others.  We did this on our sailboat where sleep is very important to the crew that is trying to sleep before the midnight watch.

With fire protection and other needs in a home, I am using for my clients a 1/2 HP 240V  pump with a soft-start. Really reliable and low power at night with the big tank. No surging and 12 years minimum between failure.  You will be lucky to get 3 years on an rv/boat pump full time.