Cistern water system question.

[okie]

Fixing to hook up our trailer to a cistern water system.
I have been to Lowes and Tractor Supply looking at their pumps and pressure tanks and no one seems to be able to help me because what I am doing is uncommon.
I will be pulling from a 1000 gal underground tank and 2- 275 gallon above ground tanks. The jet pump will be pulling less than 5' up.
How would I size my pump and pressure tank for this? My understanding is that the larger pressure tank you have the easier it is on your pump.
I was going to go with a 8.5 gpm jet pump they have at TSC that is rated at 8.5 gpm on a 25' deep well and at 5' deep the rating goes up to 10.5-12 gpm.
One website I saw says to size your pressure tank gallon to gallon to your pump output or greater, so a pump that puts out 12 gpm would need a 12 gallon pressure tank or larger.

Help please
Thank you.
Morgan

[Holmes]

Hi Okie  The pressure tank does not need to be big if it is a diaphragm tank. All it does is give the water an area to expand into so the pump can build up pressure to shut off. The bigger the tank the longer the pump on off cycles are. The tank should be for potable water not 1 for a heating system.

[Gary_C]

Best place I know of to find that type of well equipment is www.grainger.com

The answers to your questions partially depend on the possibility of freezing temps. If you have to protect all this well equipment then submersible pumps may be a better option. I prefer them to jet pumps anyway.

I don't know if you can oversize a pressure tank. If you undersize the pump can short cycle and the starting circuits can be damaged from frequent starts. But a too large just means the pump runs less frequently but longer.

The pump size just depends on how much water you will need at any one time. I think there are tables to help you decide.

[okie]

Thanks y'all.
Holmes,  how do you mean, not for a heating system? are you referring to home heat or the hot water heater?

[Holmes]

Hi I am referring to a home heating  not water heater

[Qweaver]

I'm late getting onto this thread but I'll give you a run down on my system.
I currently have 3 tanks(two are underground) with a total of about 4000 gal total capacity.  Because of the lay of the land, my tanks will all gravity feed to my pump so I am just using a small shallow well pump mounted in my heated mechanical room to provide pressure to my system.  I have a 30 gal diaphragm expansion tank and that works well for our demand.  I do have to manually switch between tanks because they are on three different levels.  I may try to make this automatic at some point with a float valve in my lowest tank.  
I currently only have a course filter on my intake but I have all the hardware to make a filter system down to 5 micron and I'll also use a UV between the 10 and 5 micron filters.  Just gotta make the time to put it together.  We have an Aqua Rain filter that will make about 3 gal a day for our drinking water.  That works well.  We are only using about 1/3 of our roof catchment area and we have never run short of water...even last winter when it was frozen for a long time.  
We like it.  No water bill and really good water.  We do practice good water saving methods but my wife takes 45 gal jacuzzi tub baths on a regular basis. She had one last night.  

[tulenut]

I'm late getting onto this thread but I'll give you a run down on my system.
I currently have 3 tanks(two are underground) with a total of about 4000 gal total capacity.  Because of the lay of the land, my tanks will all gravity feed to my pump so I am just using a small shallow well pump mounted in my heated mechanical room to provide pressure to my system.  I have a 30 gal diaphragm expansion tank and that works well for our demand.  I do have to manually switch between tanks because they are on three different levels.  I may try to make this automatic at some point with a float valve in my lowest tank.  
I currently only have a course filter on my intake but I have all the hardware to make a filter system down to 5 micron and I'll also use a UV between the 10 and 5 micron filters.  Just gotta make the time to put it together.  We have an Aqua Rain filter that will make about 3 gal a day for our drinking water.  That works well.  We are only using about 1/3 of our roof catchment area and we have never run short of water...even last winter when it was frozen for a long time.  
We like it.  No water bill and really good water.  We do practice good water saving methods but my wife takes 45 gal jacuzzi tub baths on a regular basis. She had one last night.  

You know that if you get in there with her, you will use less water, right? ;D ;D