First time pump install - 5gpm, 300' depth

[Deltafox]

I just had my well drilled and I'm looking to put in the pump myself (no prior experience doing this). I want to make sure I have everything I need to do this correctly.

The well driller recommended a Grundfos pump. Total depth of the well is 325', he suggested placing pump at 300', static water level of 30', 5 gpm. I'll be using ADS 1" 160 psi plastic pipe (that's what is already trenched to my temp trailer) 12/2 uf-b wire is also trenched from utility pole to well.

This list could be completely wrong, but this is what I've put together so far. A dole valve since the static water level is so high, torque arrestor, a csv kit with 10 gal tank, well seal, safety rope, electrical wire (not sure what type I'll need for the pump) and the pump. This setup will be for a 1 bedroom, 1 bath garage apartment for 2 people. Fixtures - 3 sinks, 1 toilet, 1 shower, dishwasher, washer machine, and outside spigot. I'm already under the recommended 8 gpm count, but I don't see myself using more than 2 or 3 fixtures at a time.

Pump I've been looking at most: Aquascience Grundfos 5gpm 1hp
Couldn't find one that was 3 wire so 2 wire will have to work.

Location is in NC, so somewhat freezing temps are occasionally an issue so will be building a well house around the setup.

 

[Reach4]

Eliminate the rope. For discussions as to why, search the forum by entering safety rope in the search box above.

6 inch PVC casing to 79 ft. Why use a 3 inch pump instead of a 4 inch pump?

Consider what the pressure out of the pump will be at 1 gpm, and choose your drop pipe accordingly.

A pitless has some advantages in addition to not requiring the well house. It makes access easier for install and service. It does not require undoing pipe fittings to lift the well. It gives access to the casing to allow easier sanitizing.

My points are not comprehensive.

 

[Sponsor]

 

[Deltafox]

6 inch PVC casing to 79 ft. Why use a 3 inch pump instead of a 4 inch pump?

I was having a hard time finding 4" available in 5gpm for purchase online - aquascience only has 3" for the 5gpm

A pitless has some advantages in addition to not requiring the well house. It makes access easier for install and service. It does not require undoing pipe fittings to lift the well. It gives access to the casing to allow easier sanitizing.

Since I don't have the space for the pressure tank, I'm going to be building a well house anyway. This will keep everything in one easy to see area for me.

 

[Reach4]

Do use a flow inducer sleeve. Cheap, and keeps the motor cool for longer life.

I sent you a message.

 

[VAWellDriller]

I'll cast another vote for a flow sleeve. Unless you plan to irrigate your yard or use a lot of water outside the house, I wouldn't go to the trouble of setting the pump so deep. I really like the Gundfos 3" pumps; I use the SQ only (not the sqe with controller), and I've never had a single failure. Given the water needs you described, I'd probably install a 3/4 HP 10 gpm at 200'...no need for a dole valve. You'd get good pressure and flow, and at 200' would have about a days worth of water storage in the casing without the well making anything. The sq has internal dry run protection in the unlikely event you did pull it down that far.

 

[Valveman]

I like VA'a advice. A 5 GPM 1HP would build too much pressure to use a CSV or PK1A. But the 10 GPM, 3/4HP would work fine. I still prefer the 10S07-12 but VA has had a lot of luck with the SQ 3" pump, and I won't argue with that.

 

[Deltafox]

I will add the flow sleeve to my list, thank you. I do have goats and plan on having a large garden so the amount of water used on a daily basis may be on the higher side. Is it the 300' depth that would cause an issue with pressure for the csv or the 1hp pump? Would the 10 gpm 3/4 hp work at the lower depth?

 

[Valveman]

It doesn't matter that the pump is set at 300', if the water level is at 30' that is all the pump is lifting from. So, when you have a pump capable of pumping from 660' like a 5 GPM, 1HP, yet the water level is at 30', the back pressure from the CSV is 272 PSI. There is about 1.5 gallons of water stored in the well for every foot of water from static to the pump. A 3/4HP, 10 GPM pump won't draw much deeper that about 200', but that is over 250 gallons of water at a time. The size of the pump and the depth it needs to be set depends on how quick the well recovers and how much water you really need. Setting a 5 GPM, 1HP at 300' would make about 150 more gallons available if needed. But if it is not needed it is a waste to put in a pump at that depth and never pull the water level down past say 200'.

 

[Deltafox]

I think I'm all set with my main order. Thinking the 200 psi poly may be better. I'll pick up shut off valves, an ispring spin down filter for after the pressure tank, and 12/2 CU UF-B w/g wire at home depot, make flow sleeve, and order the pk1a kit. Phew - hope that just about covers it.

 

[Valveman]

The SQ pump should have a built in check valve. You will need a short nipple if you want to add the additional check valve 3" to 6" from the pump.

 

[Deltafox]

The SQ pump should have a built in check valve. You will need a short nipple if you want to add the additional check valve 3" to 6" from the pump.

Okay - thank you!

 

[Deltafox]

So I ordered my pump and got all my parts. Now, the guy who has been helping me with setting up my electrical stuff is saying the pump I bought - the PSI isn't high enough and to get a 13 stage pump.

I bought the https://www.aquascience.net/grundfo...0142-3-stainless-steel-submersible-well-pumps
and he says the psi rating on the pump is 291' and then he took that - 291 x .43 = 125 psi, at the 200' it'll be lower and that my set up won't work since it needs to be a minimum of 160 psi.

 

[Deltafox]

psi rating - resulting head of the pump = 291' for this pump.

 

[VAWellDriller]

I'm not following your numbers or your math. That pump has design flow of 10 gpm at 240' head. It is capable of creating about 360' of total head. Pump curve is available on the link you provided.
The right math for this in the worst case scenario is.....IF you draw the well down all the way to the 200' pump setting and have a 40-60 PSI switch, you will need a pump capable of 200 + 138 = 338'; so you have picked a perfect pump. There is really no other way to look at this.