Pumps for very low water flow

Not a proper aquaponic question, but very similar. We have a 1/3 acre garden on the west coast of the Scottish Highlands

We are building a duck coop (with chickens) with a couple of 50 US gallon pools (200L) at the top of a 100ft'ish (35m) slopping plot. We have 3 low flow springs about 16ft  away and 7 ft lower down. The biggest spring flows about 1/4 to 1/2 gallon a minute depending on rainfall but has never run dry, the others are much more variable and never more than 1/4 gallon max often much less. We'd like to use a non powered or 12v pump and we have a 100w solar panel.

We would to pump water up to the ducks and then drain down through some biofilters, swirl filters into bullrush, duckweed beds etc to clean up the duck fouled water before pumping it back up again. Aim is to generarat some duck and chicken feed.

Vertical distance would be about 12ft and horizontal would be about 150ft. I have 12 large blue 55-gallon barrels to act as storage and header tanks.

We are not looking for fast flow, just enough to gently clean and refill duck pools and keep the sediment flowing into the growing beds.

The obvious answer is to put the duck coop below the spring line, but that means putting it in a prime veggie growing area on a small 1/3rd acre plot and having the poultry close to the neighbour's houses who may not appreciate rowdy poultry, even though they are very happy to have ducks and chickens as neighbours I do not want to test their patience at 4am on a summer morning.

In a land famous for its rains, we can go for several weeks with no rain, so rainwater feeds to the header tanks would not be reliable in the spring and autumn when we have lower rainfall, unless we built a HUGE tank.

What pump could deal with such a low volume?

I assume a DIY Ram pump would need more flow.

A Venturi pump would need more pressure?  https://www.youtube.com/watch?v=CKueWzfmN_s

So we thought a 12v pump attached to a float switch at the downhill storage that pumps up to the header tank.  Any ideas or suggestions welcome.  The photo shows the children checking the water quality of the one of the smaller springs!

Thank you.

How about a 12V diaphragm pump? You can put them behind a DC-DC converter to lower the voltage and run them slower (less noise too).

EDIT: Just don't feed them sand, it will degrade their valves and take their self-priming ability away.

1GPM pump, 12V direct drive from the solar panel/battery. Uses a max of 36W(3A)
https://www.amazon.com/SHURFLO-105003-12V-Flow-Pump/dp/B000TF2S7Y

Spring
1/4 gallon per min = 15gallon per hour = 150gallons in 10hrs (360gal if stored over night)
100W solar panel = 400WH per 10hrs

Ram pumps need a lot of flow.
Do you have any power source?
Piston pumps are slow, as are windmills.

Thank you for your ideas.

We do have mains power but I don't want to run 240v across a garden with children, pets, livestock and heavy rain!

I think the 12v pump is the way forward as John C Daley correctly pointed out a Ram pump needs a higher flow than we have.

I am thinking about an inline or external pump as they are more durable.

What are the differences between an 'impeller' and 'diaphragm' in terms of:

Durability
efficiently
Ability to slow down the flow rate to reflect our low flow springs.

Thank you

I use a 12V pump that is fitted into RV's. They are very common.
They operate as a pressure pump. When pressure builds up to a set level they stop pumping.
They work best with a 'bladder' installed in the discharge line.
They are not adjustable.
You will need a pump that can allow the pump to cut off, when the water level is low, but they generally do not self re-start.
BUT,
a submersible pump with a float switch will work well.
These will only operate when there is water and will cut out when the level drops to a set level.
They are self starting.
They use a mercury switch to do so.

> 12volts
What distance do you plan to run 12volts? Check the "ampacity" and voltage drop for various sized wire (don't  forget the return leg needs to be factored as well). A small pump shouldn't be too demanding,  but it's something that needs spec'ing to avoid surprises.


Cheers,
Rufus

I can have 12V up to 10M away.
Using big cables.
But, the pump does not always need to be at the source of the water, it can be piped across to a good pump spot sometimes