Newbie needs help re: pumps for two water sources

[jolondon]

Greetings. I live in Costa Rica and am planning on installing a 6 kw off grid system on my farm. The farm is in a very sunny area so no problems there.

The solar system will be used to power two shipping container homes I am building.

I want to use my well for drinking water and rainwater harvesting for toilets and showers. My well is around 5 meteres deep with high quality, clean water.

I want to pump water from both the well and the harvesting system to two storage tanks about 400 feet up a hill from where gravity will then feed the container homes. My questions are:

1) Is there a type of pump that can sendfrom a rainwater harvesting roof whenever water is detected flowing in the catchment pipe? In other words avoid another tank and just send the water up to the storage tank at the top of the hill? If yes, how is this accomplished with solar? My current rainwater system in another part of the property collects water off a roof into a 2 inch pvc pipe where it goes into a tank (and this is drawn to water crops). I am trying to explore if I can skip the tank next to the harvesting system. I assume the water flow would have to trigger the pump.

2) At the top of the hill I will have two storage tanks for the rainwater and well water. Assume that I need to get water from the well and the harvesteing tank. What kind of pumps do I use at the two origin points? I see that Amazon sells pumps with panels but I would rather use the solar infrastructure I am planning to build (the growatt system). There should be enough power. For the well is a surface pump best? How about the rainwater harvestsing tank?

3) And then the real mystery for me is what technology do I use to tell the respective pumps that water needs to be sent to teh tanks? Float switch? Controller? It seems like there several options but not sure which one. Also how does the pump get turned off if the tanks are filled.

I see the pumps being used very intermittently as water usage in teh container homes will not be high.

Thanks in advance for any info. I have attached a diagram of the water flows.

 

[magnet creek]

I'm not sure if I 100% understand the full setup of your system but pumps are pretty simple.
You power them with 240V (mostly) (Sure you can use 120V or DC even, but from what I think your setup is, you are going to need 240V) and they pump. I use VEVOR 3HP deep well pumps in a barrel to pump creek water up 450ft or so, no issues. You do need to run a 240V wire from your load center to your pump and you inverter and batteries do need to be able to supply the startup power for the pump.
You can use any sort of sensor to control the pump. Some sensors, like a float switch work by simply interrupting or switching the line voltage,
You can use mulitple float switches in line, so one at the bottom for low water "alarm" or shutoff and one at the top for "tank full"
You can usually use the same switch for both high water and low water, the float switch has 3 wires and just switches between the wires depending on high and low state.
For more "complicated" sensors like a flow switch, that is Low Voltage, you may need a relay, but I you may not need that complexity.

 

[gotbeans]

1) Is there a type of pump that can sendfrom a rainwater harvesting roof whenever water is detected flowing in the catchment pipe? In other words avoid another tank and just send the water up to the storage tank at the top of the hill? If yes, how is this accomplished with solar? My current rainwater system in another part of the property collects water off a roof into a 2 inch pvc pipe where it goes into a tank (and this is drawn to water crops). I am trying to explore if I can skip the tank next to the harvesting system. I assume the water flow would have to trigger the pump.

Yea but you will short cycle the pump and it'd be required to be able to pressurize itself with air on the inlet. or it'd continue running non stop with barely anything there (some form of vacuum system is preferred to do that, I think it's beyond the scope)
There's no telling how much water you are getting so there's no math you can do to get the exact pump perfect size for the amount of water being input so it doesn't immediately drain all the water and then sit running or shut off constantly.

Having a sump pump with a float switch on it in a bucket will allow it to kick on when the water is filled in there. You can do with a minimal tank in that situation I think it is easier. Many sump pumps come with float switches already built onto them.
I think it'd use overall less power too..

Your head height is pretty intense at 400ft. Is that vertical or just 400ft away walking up a hill so it may only be a 50 raise in altitude?

2) At the top of the hill I will have two storage tanks for the rainwater and well water. Assume that I need to get water from the well and the harvesteing tank. What kind of pumps do I use at the two origin points? I see that Amazon sells pumps with panels but I would rather use the solar infrastructure I am planning to build (the growatt system). There should be enough power. For the well is a surface pump best? How about the rainwater harvestsing tank?

You can do an inline pump if you are about level with the tanks. You want an accumulator tank (see picture #1 bladder tank or well pressure tank w/e you wanna call it) to maintain pressure without short cycling the pump.
- sump pumps generally have the highest head ratings at the cheapest price. I think that is better for your well and harvesting area at the bottom of the hill
at the top of the hill you can do basically any inline pump that will get you to your desired 45-55 psi
You can lookup a lot of videos on wiring a well accumulator tank to a pump. You're almost literally doing that minus the well but instead you have a tank up top, so you have two separate and they can both be smaller than the normal large well pump.

3) And then the real mystery for me is what technology do I use to tell the respective pumps that water needs to be sent to teh tanks? Float switch? Controller? It seems like there several options but not sure which one. Also how does the pump get turned off if the tanks are filled.

You can have multiple float switches. If you really don't want it to overflow I'd recommend 2 or even 3 float switches in series so if any of the 3 shut off on top of the tank it will turn off the pump from filling it.
You can use float switches on the bottom of the tank to detect when it is low.. or middle of the tank to keep it 50-100% full
You can use a metal pole to screw the float switches onto. I prefer one as tall as the tank and secure it onto the side of the tank and attach some floats on top and toward bottom so they can turn on/off depending if the tank is low/high

The other method that will probably always work is in picture #2 but this is what we would do for low failure rate.
Float switches usually fail after X time which is why I say use some in series for the filling of the tank, water kills everything.
You can use a clear plastic tube on the outside of the tank attached to the inlet on the bottom, the waterlevel normalizes itself and you can use some optical sensors to detect if there's water or not. This is usually done for things that need a very low failure rate. You can ofc add as many optical sensors as you want to know the % of water you have.