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+-- Thread: Any Shallow well experts here? (/showthread.php?tid=7283947)
Any Shallow well experts here? - Pirate - 05-15-2016
The Horrible Freight shallow well pump, sprung a leak on a welded fitting on the ss tank. A mixed blessing. The pumps output is low, both gpm and pressure. I am thinking of buying a Sta-Rite SNE-L, 1 hp pump. The SR pump that was at our old house was fairly old, and we used it for 18 years, before the motor went.
Any reason I can't use the pressure tank from the HF pump, with the new pump?
This is just for irrigation.
I just found answer online. Bigger tank = Less pump operation. Savings in elec. bill and pump life.
Think I'll buy a bigger tank.
Re: Any Shallow well experts here? - A Squared - 05-16-2016
Pirate said:
I just found answer online. Bigger tank = Less pump operation. Savings in elec. bill and pump life.
Think I'll buy a bigger tank.
I'm a little skeptical that's true. If your water consumption is 300 gallons a day, your pump pumps 300 gallons per day. It will pump less often with a larger tank, but it will pump for a longer period of time when it does.
Re: Any Shallow well experts here? - TDKPE - 05-16-2016
Pump has to move the same amount of water every day, so energy usage will be the same. Motor start-up is but a tiny bit of 'extra' cost, as shallow well pumps start easily. At $0.10/kW-hr, and a 6x startup current surge on 1200W running (1 hp with poor eff and pf), that's about .002 cents per startup for a 1/10 second event, or about 500 starts for a penny. So no, you won't save on electricity with a larger tank, and if the motor has a 'continuous' time rating, it will run forever under full load, or until the bearings dry up and seize, without harm.
Re: Any Shallow well experts here? - chips ahoy - 05-16-2016
A Squared said:
[blockquote]Pirate said:
I just found answer online. Bigger tank = Less pump operation. Savings in elec. bill and pump life.
Think I'll buy a bigger tank.
I'm a little skeptical that's true. If your water consumption is 300 gallons a day, your pump pumps 300 gallons per day. It will pump less often with a larger tank, but it will pump for a longer period of time when it does.
[/blockquote]
Same argument I have had with my neighbour, he bought the biggest tank he could find. Pump runs a long time to fill the tank, of course his wife does laundry every day, only two of them, don't know where she finds all the clothes.
Mel
Re: Any Shallow well experts here? - Robert Adams - 05-16-2016
The slower the recovery rate of your well the bigger the tank beds to be.
Say you have a 17 gallon pressure tank. And your pump puts put 3gpm. You want to fill a barrel with water. That first 17 g along isn't bad. Part way as you draw the tank down the pump will start up and add to the output of the pressure tank. Then the tank will go empty and you are only getting 3gpm.
Had you had a bigger tank you would be getting higher gpm for longer.
For irrigation you need at least 20gpm ideally. I do it with less but I can only water less area. So that big pressure tank will help for filling large needs in a short time but for irrigation tank size isn't a big deal as the pump should be running continously if it's cycling then you need a bigger sprinkler head.
Also you want to minimize pump starts. The pump running non stop is no biggie but starts are hard on the pump and reduce its life. Not just electrically but mechanically. Every time that pump starts there is a little cavitation before the water starts to flow. That cavitation over time eats away at the pump.
My well is 100' deep 4" diameter drilled in 1960 and unused since about 75.. Static level is about 50' depending on rainfall and if it's the beginning or end of summer. I am using a jet pump as being a 4" bore submersible pumps in this size are cost prohibitive.
The best output I have gotten was about 8gpm. Most of the time it's about 6gpm and at the end of a dry summer it will be about 3gpm. Now that would be better with a better pump. I bought a water ace 1hp for $100 as they were being replaced with a new model. The well sat for decades until I found it buried in the yard. There was allot of sand and sediment and rust from the pipe that took a long time to pump all that trash out. So no telling how much wear was done to the pump.
Anyway I have a 17 gallon pressure tank and it's small in some cases. I have a 40-gallon to hook up.
Now also remember with pressure tanks when you raise the pump pressure cutoff from the stock 35 psi to to say 75 psi. You will need a larger tank. The reason being is that you have to increase the air pressure in the tank to 2 psi below the cutoff pressure. So that bladder is now bigger and you have less water in the tank but at a higher pressure.