My submersible pump is over 700’ deep- anything I need to do differently?

[Richfromny]

I figured I would ask the experts here. I replaced my pump with a Gould’s 2 hp a few years ago, and it was over 4K because of the labor. It took hours because my well is over 700 feet down. I believe I have 20’ threaded pvc drop pipe but of course my last pump crapped out during a torrential rain storm so I couldn’t go look. The guys replaced the pump and control box.
Everything works well, except when I run my pool. It has an auto top off and if the water needs to run constantly to fill the pool, I am guaranteed to trip the overload in this situation, and it never happens any other time. . If I turn off the auto fill, and reset the overload, I am fine. Last point- there is a ton of fine black particles and iron in the well, I have a whole house filter and a water softener. The filter is totally clogged every 4-6 weeks so that crap is being pumped through the impellers.
My questions: how do I figure out my flow rate since the well is so deep? Why does the pump overload if I continually run water to fill the pool? My pressure tank is 62 gallons, but at 40/60 there is probably less than 15 gallons drawn down each time the pump starts and stops. Anything else I should know with such a deep well filled with fine particles?
Thanks

 

[Reach4]

1. Which Goulds pump (mainly thinking of gpm)?
2. What is the static water level in your well?

The higher the flow, the more current you draw. Get a clamp-around ammeter, and measure the current on the yellow wire from the control box. That could explain your overload while filling the pool. With a very deep well, you often limit the flow rate to where the pump is working in its normal range. A Dole Valve is a common flow limiter. However the downside is that it increases the pressure on the down pipe near the pump. Is that schedule 120 PVC pipe going to the pump?

A backwashing filter can remove the sediment being pumped, and then it backwashes to remove the accumulated sediment. If you have iron or some other things, the backwashing filter can filter those things plus doing the sediment filtering.

 

[Sponsor]

 

[Richfromny]

1. Which Goulds pump (mainly thinking of gpm)?
2. What is the static water level in your well?

The higher the flow, the more current you draw. Get a clamp-around ammeter, and measure the current on the yellow wire from the control box. That could explain your overload while filling the pool. With a very deep well, you often limit the flow rate to where the pump is working in its normal range. A Dole Valve is a common flow limiter. However the downside is that it increases the pressure on the down pipe near the pump. Is that schedule 120 PVC pipe going to the pump?

A backwashing filter can remove the sediment being pumped, and then it backwashes to remove the accumulated sediment. If you have iron or some other things, the backwashing filter can filter those things plus doing the sediment filtering.

Yes, its schedule 120 to the pump. I did a little research since i posted. I have a gould 7GS20 down there. Its 2hp and at 700' according to the specs, it does 5.2gpm@40 psi, and 4gpm@60psi.
If this ever craps out, i would probably go with the 7GS30. That would give me an additional 2+ gpm.
I have a 62gallon pressure tank, so there is probably only a 15 gallon draw down. So my pump probably runs about 3 to 4 minutes at a time when im constantly using water.
Where is that backwashing filter located? Sounds great (unless its located 700' down!)
Do i need a flow limiter? My flow seems low already.
Thanks for the great info

 

[LLigetfa]

My questions: how do I figure out my flow rate since the well is so deep?

By flow rate, I assume you mean the GPM a well can produce. Measure the water level in the well while you vary the draw. If it is a slow recovery well you could pump the well dry and then time how long it takes to recover, calculating the gallons the casing holds.

 

[Reach4]

Where is that backwashing filter located?

After the pressure tank, and before the softener. It looks similar to a water softener.

One media for just filtering is branded Filter AG. If filtering for iron also, there would be a different media.

Regarding going for 3 HP rather than 2, that may have some downsides.

 

[Reach4]

Yes, its schedule 120 to the pump. I did a little research since i posted. I have a gould 7GS20 down there. Its 2hp and at 700' according to the specs, it does 5.2gpm@40 psi, and 4gpm@60psi.
If this ever craps out, i would probably go with the 7GS30. That would give me an additional 2+ gpm.
I have a 62gallon pressure tank, so there is probably only a 15 gallon draw down. So my pump probably runs about 3 to 4 minutes at a time when im constantly using water.

How long does it run when you stop using water as soon as the pump starts?

What matters in the pumping is not the distance to the pump but the distance down to the surface of the water.

 

[LLigetfa]

One media for just filtering is branded Filter AG. If filtering for iron also, there would be a different media.

Filter AG will filter iron if it has been precipitated. It is what I use.

 

[Valveman]

Like Reach says it it not the depth to the pump, but the depth to water that counts. A 7GS20 pump pumping from 700' will produce 7 GPM. But if the water level is at 300', it will pump 12 GPM. Auto pool fill is one of the worst killers of pumps because it causes the pump to cycle on/off until it trips the overload, and eventually burns up the motor. When filling a pool the well pump needs to run continuously until the pool is full. It is better to restrict the pump to 2 GPM than it is to let it cycle on/off while filling the pool. You either need to restrict the pump to keep it from cycling when filling the pool, or fill the pool with enough water to keep the pump from shutting off. A CSV1A works great to solve this problem. However, the static level would need to be at 500' or deeper for the pump not to deliver more pressure than the CSV can handle. And going up to a 3HP would just make your problem worse.