Well water, pressure tanks and filter issues

Users who are viewing this thread

NickNB

New Member
Messages
2
Reaction score
0
Points
1
Location
Saskatchewan
Hi Guys,

I've got a interesting problem with our well water supply setup and hope some of you might be able to guide me in the right direction.

Some info:
-New well, 500 ft deep, produces 5-8 gpm, lots of reserve
-Very bad colour, iron and turbidity which required alum injection + media and carbon filters. Filtration system now works great and don't want to mess with it now as it took so much work to get perfect.
-Setup is well water to 10 gal pressure tank w/switch to large contact tank with alum injection, valve to choke flow to 3gpm, then media filter, carbon filter then to house.

Problem is for the filtration system to flocculate and operate properly, max flow rate through the system is about 3 gpm, not enough for our family house. More than a couple faucets and something starts to give.

From some research online, seems like the couple options are:

1) Open tank after last filter, with float switches or similar to operate well pump. Secondary pump required after open tank to pump to house. This seems simple enough in principle but would require some electrics and safeties to prevent overflow and so on.

2) Very large pressure tank after last filter to provide some reserve water capacity with some pressure behind it. Presume first small pressure tank and switch would still operate well pump. Not sure how well this would work, but would prefer it to option 1) as it seems there is less that could go wrong, less moving parts.

Your thoughts on the above, or possibly other options i should consider would be appreciated.

Thanks
Nick
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
You should "develop" the well by pumping water from the well -- not through any filter-- for a day or two into a ditch etc. That will help wash sediment out. Maybe that has been done.

Have you sanitized your well? http://www.moravecwaterwells.com/index.php/maintainance/disinfection-and-testing is my favorite method.

Do you have a water test? Your filter sounds impressive.

I understand I did not address your questions.
 
Last edited:

NickNB

New Member
Messages
2
Reaction score
0
Points
1
Location
Saskatchewan
We did a significant amount of drawing down /cycling of the well while we were finishing the construction of the house. We must have recharged the well 50+ times. It help a little but not significantly. We had the well shocked a couple time also.

Apparently the problem we have is not common and is similar to colloidal iron. We've had about half a dozen rounds of water analysis done, no harmful issues or bacterial, just high iron, very high turbidity (100+NTU) and color. We've got it down to <1 NTU, tastes great and checks out well from the water testing side also.

We were so happy just to have usable water that the low flow rate available was a minor inconvenience in the big scheme of things. Although our exact situation may be a bit different, I presume it would be the same issue as someone with a low yielding well that did not meet their flow requirements.

Any thoughts would be appreciated.
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
I have no experience, but based on reading etc I have some thoughts.

#1 would be your normal solution. You would want the cistern or tank to be covered to protect it, but you would want a tank to be vented. You would need to have the water protected from freezing. The tank would either have a submersible in the tank, on its side, or there would be a shallow-well jet pump outside the tank. That pump would be controlled by the pressure switch and would have a pressure tank.

The well pump would be controlled by a float switch in the tank/cistern.

#2 could work with some limitations. Note that a typical pressure tank has a "drawdown" amount of about 25% of its nominal size with 40-60 PSI, and maybe a little more at 30-50 PSI. But instead of a switch with a 20 PSI differential, you might want to run 55-60 or 45-50 PSI. That might require an electronic pressure switch, since I don't know that normal mechanical switches can do that.

So if you had a Well-X-Trol (top quality brand) WX-350, 119 Gallon, Size 26" X 62"
Drawdown @(30-50 PSI) 36.8 Gallons
Drawdown @(40-60 PSI) 31.9 Gallons
you could set the pressure switch at 45-50. You would have a reserve of about 26 or 27 gallons once the pump turned on. That would be in addition to whatever the pump can provide during the consumption of the reserve. That seems workable for most uses except big sprinkler lawn watering, fire fighting or hot tub filling. The gallons/pressure drop is probably not linear, but I am approximating. You could add a second tank in parallel to increase capacity. The pressure tanks would not have to be identical.

If you used two pressure tanks, that would help you use cheaper pressure tanks because you could take one out of service and replace it on a less urgent basis.
 

Valveman

Cary Austin
Staff member
Messages
14,583
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
I don't think you would be happy with a large pressure tank after the filter. With a 50/60 pressure switch setting the tank will drain to 50 before the pump starts. At that time the pump will be adding 3 GPM while anything over that comes out of the tank as the pressure continues to decrease to maybe 30 PSI. Yet this will only give you about 20 gallons extra for each use.

3 GPM is actually 4,320 gallons per day. If you had a cistern type storage tank with 1,000 or 1,500 gallons in it, a separate booster pump could supply as much GPM as you need at good pressure. Even a 100 gallons cistern tank would deliver as much as 5 large pressure tanks. And yes you would need some electric and plumbing to add the extra pump. But a Pside-Kick kit with a CSV and a 4.5 gallon size pressure tank would be all you would need. You could either use a jet pump drawing from the storage tank or a submersible laying in the storage tank.
 
Last edited by a moderator:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks