I'm not a professional, but I can offer a little bit in the way of information.

How much volume or output should you expect to need from your well for a 24x24 up to a 30x96 greenhouse with an automatic watering system (or not)? I don't know but I water an entire landscape off of my deep well, I can't imagine that a standard deep well wouldn't be enough. I think that most irrigation and misting controllers are designed so that the zones come on at different times, making the water demand steady throughout the cycles.

What is the minimum GPH (or GPM?) and minimum pressure you should plan on needing? I think my well is typical at about 10gpm and 25psi. My guess is that you'll need at least 20 psi.

What do you do if a drilled well doesn't produce the volume or pressure needed? The volume can be controlled by the size of the deep well bladder tank(s). I think that you can add bladder tanks to add volume. The pressure is adjusted by changing the pressure in the tanks and/or adjusting a pressure switch.

Are booster pumps used? You could do that if the pressure is not sufficient for irrigation or misting. Some systems work better at higher pressures. I use a booster pump to increase the pressure across the RO system - without it there is not enough pressure to effectively mist.

Are there other options to supplement or back-up your water supply? I've heard of rain barrels, cisterns and stuff like that.

I guess that the professionals will chime in...

I think I need to have my well checked by the well company to see what it needs. I timed filling a five-gallon bucket at my kitchen sink and it took five minutes...so I get 1 GPM? Come to think of it that was before we replaced the worn out bladder tank with a really large one and the switch I think is set at 40psi. So I should test it again. Hopefully the well really is deep and maybe just the pump needs replacing and/or more tanks added. The pump and the tank were both over 20 years old. For some reason I have more pressure upstairs than at the kitchen sink right over the tank.

I don't actually want to have a greenhouse here...hope to get a better laid out property and want to make sure it has a good water supply. But if not I may have to start it here first.

"across the RO system"... what is RO? So the water goes from the pump to a booster pump to a misting system?

Thank you for your reply. :)

RO is reverse osmosis. My well water is so hard that when you mist with it, calcium residue rapidly builds up all over the GH glass and the plants. It's a mess. The RO takes out the calcium. A potassium water softening system would do the same thing.

So I boost the well pressure to 75-80psi with the booster pump. There is a 50psi gradient across the RO membrane, giving me about 25-30psi in the bladder tank for the mist system. Without the booster pump the pressure on the other side of the membrane is 10psi or less and the misting system doesn't work well at those pressures.

BTW, I don't know that this is an ideal system...I go through at least one $75 membrane every 6 months.

Hmmmm...you just brought up another thing I hadn't thought about yet...we have very hard water too.

I will have to see what kind of "expert" our local well guy is...maybe he has even worked on greenhouse situations before and will have some suggestions. Also possibly at Griffin's Greenhouse Supply they have experts (who aren't just salesmen) to help you make the right choices. There is also a perennial wholesaler we know here who I think will be willing to give us tips as he is a super nice person.

Daisy, if you learn anything that might be useful let us know!

I have a 55 ft well that puts out 15 gpm at 75 psi. My greenhouse will be 52x18 and I am sure that will be enough to water. I also use it to water around our place. The well will support one hose turned on full without ever running out of water. Two hoses on full and after 25 minutes they start to spit air. I can run two impact sprinklers forever, but add a thrid and after an hour they start to spit air. The property also has city water hooked up to the house and though it would be costly I would use it as a back up system if ever needed. Always plan for a backup system.

If you really only have 1gpm you would want to get a large reserve tank. I believe you would need ti sue a two pump system. The pump on the well would fill the large reserve tank while another would service your greenhouse/nursery watering needs out of the reserve tank.

You might want to post this on the Irrigation thread as there are many knowledgable well and pump people over there.

Good luck,
jb

Thanks, jb. I didn't realize there was an irrigation forum, must have overlooked it on the list. I will check over there too.

This well subject just has me so confused. Where I lived before I had a 300' artesian well and we could fill our pool, take showers in two bathrooms, and run the dishwasher and washing machine all at the same time and never notice any flucuation in the water supply. I should have appreciated it more. :) I just saw a real estate ad for a place advertising it has a "new artesian well delivering a full 5 gpm" and that didn't sound like much to me!

Maybe the well company down the street or the county co-op guy will have some information on the water supply in this area.

stressbaby, if I learn any good tricks & tips I will be sure to post it in here. :)

Every well is different. There are two things that control how much water you have to use. The available water in the ground which is based on recharge rate. The recharge rate is how long it takes for water you've pumped out to be replaced. The other is the pump and storage system you have in place.

Most people have a pressure tank that is refilled from the well as it is used. This tank must be housed in a bldg that can be protected from frost. The capacity of the tank is determined by what your GPM is and how much water you will need to use in a given period. Low gpm and high needs would require a very large tank.

I have a variable speed Grundfos pump. The variable speed pump does not require a pressure tank. I have only a 2 gallon bladder tank. Same kind you have on your hot water heater. It lives in a catch basin under ground. Saved $900 by not needing a pressure tank and the bldg to house it. The variable speed pump delivers only enough water to maintain a certain water pressure. It is computer controlled, you just set it to the desired water pressure. As you open more valves it spins and faster and pumps more water.

Of course in any system you could open enough valves and run your well dry. Though dry is only a temporary state. If I do that with my system I just have to shut all the valves and wait a few minutes.

Hope that helps. It will really get interesting when you find the piece of land where you want to install the well and all that. The drillers up here were very helpful.

Good luck,
jb

jb, I think it is the available water in the ground and it's recharge rate that has me the most worried. I lived in OK and paid a lot for a dry test hole. Out of frustration we hired a 'water witch' ;) and drilled a well where he said there was water. We barely had enough to flush a toilet...and a very long recharge rate. :)

Up here we have a 'drilled well' (no idea on depth) with a 30-year old Sears submersible pump. It used to kick on and off all the time, then the water got slower and slower and less and less. Finally we replaced the bladder tank with the largest one Home Depot sells and got a new pump controller box from Sears for that pump. So now the only old thing on the system is the pump down in the well. I believe the water volume and recharge rate on the tank varies depending on the pressure you set. And ours is in our basement...after all this is the great white north. :)

Now I can fill my coffeepot without running out of water, you don't hear the pump anymore and we don't seem to have any problems this year watering all our flowerbeds. We just still don't have much water pressure in the house. I could turn up the pressure on the tank to see if it helps, but then the tank volume goes down and we put more stress on a very old pump. hmmmmm....I just realized I think we get more volume in our garden hose than we do at our kitchen sink. Maybe my pipes are clogged or sized wrong.

Anyways...I think I need to have the well inspected. Maybe it just needs a very old pump replaced...or also needs cleaning or relining or whatever else they do to wells. Hopefully it won't need a completely new well drilled. At least I would find out the depth of the well. I just don't want it to fail after I put up my greenhouse; would like to fill my 10-cup coffeepot in faster than 30 seconds; would like the shower to rinse the soap out of my thick hair and I would really like to use the 2-person jacuzzi that is upstairs. :) Gotta call the well guy.

Your pump sounds really cool. If we get to move I hope to have a separate well drilled for the greenhouse with a pump like yours.

Just a few added thoughts.
We also looked into having a well dug as a backup for our nursery. Our area is on a large bluff so to speak with a major river with in 10 miles. We were told that the well would have to be about 900 feet deep. While other folks on the other side of the river can get away with 300ft. The estimated cost was $9000.00. Luckily we have county water and a pond (just in case).

Most auto water system will require 40lbs of pressure to operate. We have 40lbs at our main house. We can water through drips about a 700 plants at a time at .5 gallons per drip per hour. We currently have 12 watering zones total. Each zone can run for 20 to 40 minutes depending on the zone. Add it up and the water runs for 4 to 6 hours a day during our peak usage. I wished I knew how much water we save. I know itÂs a lot and a must have for our operation.

RO systems. I looked into them also and (and we have one under our kitchen sink) have not found any system, that we could afford, that would supply us with enough water in a day to run all our drips. You would have to have a massive RO system with large holding tanks and pumps to store enough water for use at 40lbs of pressure. Also RO systems waste a lot of water. The contaminates are flushed from the system down the drain or yard, whatever. An RO system would run water almost 24 7 to keep up. That defeats the drip system.

Are ponds, rivers used. Absolutely as a backup in our case. Some nurseries build retaining ponds for water storage. And you get to fish in them as a bonus.

My one piece of advice is that you look into the future and determine your water needs will be in a few years.
Instead of running a 3/4" line you may want to consider 1" or 1 1/2" main to your g/h. It may cost more upfront but you'll be happy you did it later on.

It sounds as if you are starting a nursery and you should consider were you are going to install your horse head spickets (sp?) off your main line also. The more you have the less 100 foot hoses you have to deal with when you hand water, ect.

Pop me an email if you would like to talk more specific.

Most people around us have 150 to 300 foot wells. We had enough money to go 200. Not sure what we'd have done had it gone over that. We were extremely fortunate. I remember when the drillers called me at work at 3:30. They were already finished and on the road. I asked how it went and how deep the well was. 55 ft with a 15 gpm. I couldn't believe it.

In total the well, pump, 800 feet of 1 1/2 inch black poly, seven frost free hydrants and the electric lines cost $12,000. Those are northwest prices. Your mileage may vary.

jb

Mylu, let me clarify...I don't use RO water for irrigation, only for water going through the mist system. You are right, to use RO water for irrigation is not practical.

SB

Stress how big is your g/h and storage tank for the RO water?

JB I thought in the NW you all just put barrells out to catch the rain :)

This year we don't even need the barrel. Haven't had to water anything other than container plants. If this keeps up I may sell my hoses on Ebay.

jb

Mylu, my GH is 20' x 23'. The bladder tank is 47-50 gal.
SB

DaisyLover,
This might be obvious, but how often do you change your sediment filter on the well line? I'm in NH too, whenever the pressure starts dropping I know it's time to replace my water filters. The micron size of your sediment filter should be around 30. Any smaller, they clog faster and reduce pressure. Mine last about 60-90 days before my pressure starts tailing off. Just something to check out.
Dave

Dave, it couldn't be that easy...we don't have any in-line filters in this house. Which would mean if anything is clogging up it is all my faucets and all my water pipes.

DaisyLover,
I can't believe someone wouldn't install a sediment filter when water is supplied by a well! You might have exactly as you described! Clogged fixtures and piping. You should take a closer look and see if there is a filter partially hidden somewhere that you may have over looked. If you find it, that's most likely your problem. Bad news to not have sediment filter in a well water system.
Dave