Submersible pump setup for garden watering

We have an old water well that I could use to water 3 veg gardens 150ft away.
What extras will I need?
Any filters or check valves?
The pum would have to pump up around 10ft and then all horixontal for 150ft.
Would 1/6 HP be enough? Would 1/4 be ok, what is too powerful for hoses?

I'm presuming that only the pump can be timed, there is no way to split the different zones into separate waterings after that as there is no trigger for the pump to come one? So, there is no way to control flow when pump is on, it has to pump at full flow?

Could I instead run polypipe from the pump to the garden and then split it into 3 taps on a piece of wood near the gardens that hoses can then be attached to?

 

I think you will need at least a 1/2 HP to over come that 150 feet resistance. Yes you can split the flow by using various fittings. You can also use valves to control the flow.

 

How deep is the well? Do you want to have the pump above ground or a submerssible one down in the well? What flow volume (gallons or liters per minute) do you want?

A lot will also depend on the size of pipe you choose for the 150 foot run. Smaller pipe will have a lot of resistance especially as the flow rate goes up. Black poly pipe is available in long coils and is inexpensive. The smallest I would consider is 3/4" but would probably run 1". It's available in different pressure ratings. I'd go for the higher rating, usually 160 or 200 psi, as it's more resistant to damage.

 

It's a shallow well so I think it's only 20ft maybe. Water starts at around 8ft-10ft below surface but difficult to see as the lid is concrete so I can't take it off easily.
Presumably, I would have to drill a hole in the conrete for the pipes to fit through and drilling a 3/4 or 1 inch hole in concrete might be difficult?

Can the pump run if there is no flow, ie the valves are closed off?
What I would think of doing for example is having a timer on the pump for say 30 minutes. Then a separate timer on the 3 zones for 10minutes each but timing would never be exact so pump might be running whilst all valves closed for a short while?
I doubt the pump would have enough pressure to water 3 zones at once?
If all valves were closed, wouldn't the pump blow off the hoses with the generated pressure or is there a pressure relief on these submersibles?

Lastly, the well has been sitting there for many years unused. Might have a load of green stuff on the top. I'm guessing it would need a shock treatment before using on the garden?
Is there any danger with the air in the well between the water and concrete lid heating up in summer and causing bacterial growth?

 

To prevent the pump motor from cycling too much, I would add a pressure tank to the set up as well. You can set your outlet pressure via a pressure switch. Is this a 30" bored or 4" drilled well?

 

It`s a surface well, don;t think it ever had pipes to the house.
The opening is maybe 3ft in diameter at the top...covered with a concrete lid.
I guess it`s getting expensive if a pump, tank, and switch are needed.

 

You could just use a generic pump like a pool cover pump and just let the water flow over your gardens... soaker style. If it doesn't pump fast enough.... leave it running longer.

If you're planning on using sprinkler heads then you'll need a bigger pump and a pressure tank.

I have a pool and when it's covered I use a decent sized pool cover pump to water the gardens. Not a drop gets wasted.

 

Be cautious when lifting that lid on the well. I can guarantee you there is a female black widow spider nesting there. Wear gloves.

 

LOL.
Would it be necessary to shock treat the water after 30 years of no use? Or just pump it into the garden and wait for new water to replace it? Just worried about the pump getting clogged.

 

I used to have pump clogs. I've taken a square milk crate and wrapped it in screen. I set the crate on the cover with the pump in it.

If the water smells clean.... use it the way it is.

 

All your scum and dead rats will be on the surface for the most part and you will be drawing from several feet down, so you could scoop it out. I would not use it as potable water, for sure.

 

Do outside pressure switches exist? In case I can pick up an old tank and place it near the garden then connect it to the pump?

 

It's common for irrigation pumps to not use a pressure tank. They just use a pressure switch. The key is to have the pump matched reasonably well to the load (water use) to minimize on/off cycling.

I have not seen outdoor pressure switches. Most often I've seen people build a well house to protect the equipment. I've also seen a upside down bucket placed over the switch to protect it from the elements.

 

Is there anywhere that suggests what hp to use vs length of pipe? Almost everything I can find only has flow rate and maybe feet head. 2HP was suggested above for pipe resistance but that also makes it a bit more expensive.
The pump would have to lift about 10ft and then pump along 100 ft in maybe 3/4 inch poly pipe.
The split into 3 zones of 3 soaker hoses so I'm thinking 300 GPH would be more than enough but could be double if needed for a proper hose or single zone.

 

Is a pressure relief valve needed in case the tap is not open when the pump cycles?

 

It's not simply a matter of hp you also have to consider the pump. Think of the pump almost like the gearing in a car. For the same horsepower some can be first gear (high pressure but not a lot of volume) while another can be third gear (not as much pressure but more volume). The annoying thing is that the resistance through the pipe changes with the flow volume. With soaker hoses you are not going to need a high volume. I would look up the specs for your hose to see how much water it will use then find a pump that outputs close to that.

 

Thanks. Only thing I don't understand is how the pump can cycle if the outlet is closed?
Ot let's say the pump is 1000GPH but the hose can only output 300GPH.
Doesn't that cause extra pressure to build up in the pipe or does the pump release that somehow?

 

No. I means the pump has the "capacity" of moving that much water. I still say a pressure tank will solve what you are most worried about and give you a constant flow of water rather than an impulsed flow every time water is demanded. The pressure switch will reduce the pressure from the maximum rating to the pressure you want. The pump won't cycle with the outlet is closed.

 

I can probably find a used one somewhere. Should the pressure tank go at the well end or at the garden end (150ft away)?

I'm just interested in what a pump does if all outlets are closed without a pressure tank system? ie it's trying to pump water but the water has nowhere to go? So, how does it cycle off in that scenario? What happens to the water it's trying to pump or is it restricted by the pressure pushing back.

 

A pressure tank is optional. It just smooths out the flow and helps minimize the pumps on/off cyling. A pressure switch is almost mandatory. It senses the water pressure in the pipe and turns the pump on and off as needed. So, when you turn off a hose the pressure will rise and the switch turns the pump off. Open the hose and the system pressure will drop and the switch will turn the pump on.

 

Should the pressure switch be at the hose end 150ft away or right next to the pump? Does it matter?
Presumably pressure is lower at the hose end?

 

Pressure is pressure, no matter where it is located, but more favorably at the pump.

 

I like to have it close to the pump. If you locate the switch far away there is a chance that a restriction in the line between the pump and switch can cause a lag in the switch's response.

 

Any ideas on how to lift this lid off the well? Threaded rod or rebar and lever it off?

 

Often there is a lip helping to hold it in place. I lift one edge and shift it to the side just enough to clear the lip then slide the lid to the side. Generally there is no need to actually lift it.

 

Yeah but I cannot lift it by hand, I tried, too heavy so need some way of getting it off.
Can't move it easily sideways if there is a lip... won't budge

 

A bar through a lifting eye may give you enough leverage to lift one edge and slide it over. Other than that you can work like an Egyptian. Construct a tee pee frame and from the top hang a block & tackle or winch. Easiest and safest would be a machine like a front end loader or excavator. Just be careful if you will be lifting the lid. Your lifting loops look good but I've had many of them fail unexpectedly. You don't want to be near it when it falls.