ShopTalk Monday: Greenhouse Water Engineering

Greenhouse Development work continues at Uretopia as we wend into Summer.

To recap for newcomers, about two years back, son George II and I were messing around with Ground Screws and (in a flight of fancy) I decided to put up a greenhouse.  A lean-to against the Music Studio’s west (outside) wall, it seemed like a neat place to put in a survival garden lite.  It was close to the kitchen, water nearby, and so forth.

Then the Engineering Gene kicked-in.  After a very short time, it became clear (although we had suspected it from our earlier hydroponics sessions in the bigger greenhouse in the dirt garden area) the pH of the water from the local rural water outfit just wasn’t suited to high-output plants of the blooming sort.

The pH runs around 8.0 to 8.2 in the summertime and veggies like the high 5’s to low to middle 6’s in the blooming period.

Standards Have Changed

A note before today’s tale continues.  It has come to my attention that ratings of air conditioners have changed – this much after the facts of what I’m about to recount.  Most of us (over age 50, or so) remember air conditioners were rated quite evenly.

Today, however, there are two types of ratings.  As AI explains it:  While the ASHRAE rating gives the hard numbers of the BTU output, the DOE rating is more of a “real-feel” rating. This means you can be sure your AC unit is more accurately rated, which means better cooling and greater efficiency.”

Thus, even if you are a child – under age 50, or so – then close study of this article – ASHRAE vs. SACC BTU Ratings | Sylvane – will get you a long ways toward understanding how Ure’s normally careful calculations came up “10-degrees short” in the first iterations of this project.

Engineering Takes Over

After purchasing – but them having second thoughts about a small reverse osmosis system for the greenhouse (because of water waste in keeping the system going – about a 9:1 ratio of “neutral water” to even more alkaline blow-by) I hit on the old Rainwater Barrel solution.

Two rain barrels and some gutter work – and the system was complete.  But laziness is ever-present. So, to end the daily hassle of filling up watering cans, I decided that putting in a modest 12-volt power system would allow all kinds of refinements.  For example:

  • A small-scale LED motion-activated lighting system could be installed.
  • So could a larger work light, or three.
  • Being on 12-volts also meant I could install use RV/Marine water pump. These don’t draw power until the pressure drops.  Automatic on-off is music to the Lazy Ure’s ears.  (I like to think of it more as “personal efficiency, however.)
  • This suggested that I add-in a good-sized lithium battery (100 Ahr’s worth) so I could water my plants with a metal kink-proof hose.
  • Two solar panels were added as well, to keep the lithium battery topped off.  And when the sun wasn’t sufficient, a high-quality charger (to float the battery of AC mains power) did the trick.

It all worked dandy, except for a half-dozen times in 2023 when we didn’t get enough rain to keep the rain barrels filled.  (Two of them, 50 gallons each, tied together at the bottom (a garden hose Y worked fine). A cup or two of vinegar brought the pH down to an acceptable range.

For summertime cooling – when it gets upwards of 110-115 in the greenhouse – we added a swamp cooler. But that kept the room moister than desired.

This year, we took out the swamp cooler, put in a portable 8,000 BTU air conditioner which is able (at present) to keep the greenhouse about 8-degrees cooler than outside air, best case.

There’s more to this evolving design – which we will get to later in this report – but for now, I wanted to read you in to how this all got evolving because it’s a fairly interesting story. Mission creep.

Making the Air Conditioner Better

The basic a/c unit (bought at a discount on a Prime Day was pretty good. But it has a glaring design issue.

See, when a compressor type A/C unit runs, it creates condensation on the coils.  If the unit were allowed to run continu0usly, the evap unit would ice up and there goes the cooling.

That is why most air conditioners “cycles” between regular air (to blow off the icing) and that icy cold air when the compressor is running.

It worked OK, but I wasn’t getting my money’s worth on the cooling because of the cycling.  In this particular unit, there is a “heat exhaust pipe”.  As the machine defrosts the coils, water is collected and evaporated into a 5 1/2 inch duct to outdoors.

A review of the manual reveals that you may improve the “on time” by getting rid of the melted water some other way.  Specifically, there was an included drain hose about 18 inches in length which was designed to go into a bucket.

When full, of course, this led to violation of Ure’s Lazy Personal Efficiency axioms.  We simply will not tolerate systems that require human intervention and work.  When we sold our old Beechcrate, for example, I had about had it with the manual (Johnson Bar) flap system.  It was like reaching down to pull on the parking brake of a VW Beetle, every time you wanted to land somewhere.

[Homework for New Home HandyBastards: Read over here on what Johnson Bars are and how they showed up in Beechcraft and Piper aircraft, as well. We just sort of assume you have first-hand knowledge of such arcana, but if you’re under 65, it’s an excusable offense, actual parenting and independent study being stealth outlawed since the Johnson (different kind of bars) Administration.]

Kicking the Bucket Work

If you’re following closely, we’ve built the greenhouse, got it to semi-self-watering with rainwater and then damn near fully closed cycle from air conditioner coil water.

But there was still a twice to three times daily emptying of a 2-gallon bucket.  Which demonstrated that a) if not emptied, it would dribble over onto the concrete tiles (greenhouse floor) and b) then spills all over the bucket operator who tries to empty it (barefoot and naked) after two drinks at bedtime.

There had to be a better way.

Out came the old training in TRIZ, the Russian method of Invention.

[Another Newbie Reading Assignment is here – on the workings of TRIZ]

Truth is, for me (*having lived on a 40-foot sailboat for 11-years) there was no TRIZing to it.  I wanted a device that would automatically pump water.  Why, that was like a ….sump pump? No.  Too big, not 12-volt power.

Well, then how about an automatic Bilge pump for a boat then?

You mean like this $38 from Amazon goody?

The Bilge pump has a ground (black) and two “hot leads.”  The blue one is the one you want because there is a float under the blue bottom cover of the bilge pump which turns the pump on when the water gets too high.  The red wire just turns on the pump regardless of water level.  You could set up a momentary contact switch to that off your 12-volt system.  I’m still going to counseling to find out if I am really that paranoid that I want the second switch.

Thing is, when the water level rises (far enough) the pump float comes up, the electricity comes on for the motor, which then sends the excess water up the 1 1/8th inch flex pipe where the outflow goes into the same screened water inlet as the rainwater downspout.  You can see how the cobble-up for testing laid out here:

Oh, it’s a mighty flow and it works dandy.

By like our favorite physicist saysThere’s just one thing…

Namely, when the pump kicks off (when the float runs out of water to float the float switch) that leaves a 39-inch water column in that 1-1/8th inch hose.  And that’s the problem why?

“Can you just get on with it, Old Man?”

NO! I am teaching you about design here, so pay attention to what happens next:  The water column runs backwards, down the hose!

Who gives a shit?”

Well, you should.  Because it will be enough water to refloat the float and turn on the bilge pump again.

Quick, Genius: how do you fix an oscillating water pump which is spazzing out all over the greenhouse floor?

“Put in a different float valve?”

No! (You aren’t thinking in TRIZ mode, yet!)  The easiest solution is a bigger container OR a one-way check valve for 1 1/8th inch hose.  Like this one.

If you check valve doesnt have visible markings on it blow in one end and then the other The end that is easy to blow in goes toward the source bilge in a boat or the greenhouse water holding tank in this episode The end you cant blow in is the outflow end $18 bucks for a pair of them on Amazon<strong> Double clamp yes two clamps slightly offset from one another when doing a marine installation where your live and the boat may depend on quality of workmanship<strong>

In a big ocean sailing machine (like mine) this kind of check valve (but further up the Marine Grade food chain was critical to keeping the outside seawater from running down the bilge pipe when the starboard rail was underwater.

Check valves stop looking overpriced when you’re on the Sausalito Beat in San Francisco with the masthead wind is piping 30-35 knots. A calmer day ride is chronicled here, if you wonder what it’s like “out there.” Inside the Gate where the winds funnel every afternoon, sucked in my rising air inland…sailing stories another time.

Fixing It Right

The First solution is to work the math.

Taking the bottom protective cover (blue) off the bilge pump, we make a few measurements and see if this well-designed solution clicks-on at one level, and then clicks-off about 1/8 to 3/8th’s an inch lower. Maybe a quarter inch?

Next come the calculations (perhaps Sabine could check our work?).

The area of 1 1/8th inch circle is an outside diameter, so we will assume 1 inch inside diameter and toss in a fudge factor (no nuts, please).

Circle area = ? × r² = ? × 0.25 in² ? 0.7854 in²

Hmm… let’s call the diameter 0.9 inches then.

The key design question is: “How much water is in the pipe?”

Water volume: 39″ of column times 0.9 is 35.1 cubic inches.

If we are designing a tub for water that will not cycle, then our minimum size would be:

Min size:  35.1 times 8 (because there are 8 slices of 1/8th inch thick in a one inch of water column, following?

Which means I can order something on Amazon, like these plastic storage tubs which are 18.5″L x 14.4″W x 10.5″H.  Making their area 18.5 times 14.4 (266 square inches) less whatever the displacement footprint of the pump is…

It will be close.  But remember we added some fudge to the 0.7854 area, which could be a working bilge/basin size of 245.04 square inches, so my actual tube may, or may not work (it should).

If the switch dead banding is greater than an eighth of an inch, we are In Like Flynn. At a quarter inch of differential, we can be down to a much smaller intermediate water tank.  But if the wall thickness is less than 1/16th, then we could be wrong the other way.

That’s why the check valve – and to keep outdoor creepy-crawlers from making their way down into the local bilge proxy.

Extra Credit: Using this basic math, and measuring the water precisely, calculate the actual wall thickness of the 1-1/8th inch tubing.  (Childs play for reader-engineers like Al and Art but we won’t disqualify them from entering because they are REAL engineers, and we don’t rule out competence unlike some companies and agencies… let’s not go there.)

See Why Engineering is Fun?

It’s a way of thinking that can be applied to all sorts of home problems.  A few key engineering concepts (vector of force calculations are fun, too!) though the world isn’t totally your oyster, you can still make a big enough, powerful enough, and durable enough machine to move things.

Who was it, said Give me a long enough level and a fulcrum and I will move the world for you?

Answer from AI:  “The Greek philosopher Archimedes is said to have said, “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world”.

One for the Road

Elaine came over to the office Sunday holding the first Texas-Sized Magnolia bloom of the season:  “What do you think?” she asked.

Dang!  Measured a little bit over 10-inches from petal tip to petal tip.

I figure in about another week, maybe two, our little Magnolia will be loaded with blooms, but you can see some of the early bloomers are doing well:

For a second of scale, that bell and holder on the pole, lower left over one of the wireless solar surveillance cams, is about 14-inches tall and the tree is on the far side of the driveway, about 20 feet further back.

Seems like I got the “secret sauce” right this year:  Fertilize in March, let the April monsoons wet it all in, then let’s have a sunny May to drive a great set of blooms this year.

There’s a very weak scent to the Magnolia blossoms.  The Gardenia bush outside the 180-Room?  That one is blooming well, too.  Same fertilizing schedule for both this year.  (SouthernGRO Azaleas, Camellia, Gardenia Fertilizer 04-08-08 – 4lb Bag.)

Nothing like opening a baggy full of fresh gardenia blossoms – stored in the fridge – to have a nice smell to the house with that first cup of wake-up juice.

Of course, if you live in a chicken coop, in town, a spritz of an air freshener and instant coffee just ain’t quite the same… Not Ure fault; maybe you like standing in line for coffee and don’t get downscaling? You will make more money, sure. But no lines around here, except weekends at the Big Box stores when the urbanites come to work on their bug-out joints. Local people are more likely to understand part of time management is looking at a calendar and clock. Just saying…

ShopTalk Sunday from yesterday is in the index here.

Next weekend on “ShopTalk: Instrumentation of Tomatoes!”  as we pull the night shades over the monitor to hide it…

Write when you get rich,

author avatar
George Ure
Amazon Author Page: UrbanSurvival Bio:

30 thoughts on “ShopTalk Monday: Greenhouse Water Engineering”

  1. I always find your technical teachings and project descriptions fascinating and today being no less so. Until you got to the part about emptying the water bucket naked and barefoot after a couple drinks at bedtime. The mental image will be in my feeble mind for quite a while.

    Stay safe. 73

  2. Yo Aquaman,

    Can I get a witness ?

    I needz a review the LifeStraw Community. Its a pricey piece of kit(4 hundred$), but it handles – purifies mass quantities of dirty water.

    Side note/bet -calculated an Over/Under on the Cosmic Chicken Bunnies return to Writing on Urb. Surv. yet ?

    Too The Shooters then !! -

    • use a stick’s cheaper.
      plants filter water all the time it’s their job like a straw.. root side towards the water..

    • I saw mixed results with Life Straw in Africa 20 years ago but that is a long time and before the Life Straw Community. You might want to take a look at the Sawyer filter line. Very turbid water should always be settled before using any of these filters or you will have short filter life. I think you can backwash the Sawyer filters to extend filter life.


      • Mucho gracias BIC and Loob, no really thx, appreciate youse two.

        Presactly what I was looking for/needed, much obliged.


  3. I love the magnolia’s… love the little air well to.. I never thought about doing that with a portable air conditioner.. the best one is a dehumidifier with a pump in it..
    around here we have japanese snow ball bushes.. beautiful and they are more like a tree than a bush..
    Base Recipe:
    Maple sausage..
    I usually use a pork but.. grind it coarse first then freeze it for a half hour then grind it again with a smaller grinding die.. if your going to make link sausage.. its better to grind it till its.. real fine mix in the powdered milk as a binder.. if your going to make skinless suasages.. then get the plastic tubes.. half inch.. and then when you get them to 165 degrees cool them down and take the tubes off of it..
    I for one buy my seasonings already mixed up.. its actually cheaper to buy the pre mixed seasonings than it is to not.. I believe the only thing not in it is the sage..
    and that will last you a few years.. mix up the amount per pound.. then only mix up one pound.. take a little bit of it.. and fry it up see if there is to much seasoning in it or not enough add what you like then you have the seasoning the way you like it.. I like mine a little mellower than most..

    1# Ground Pork below is the ingredients per pound..
    1.5 tsp crushed sage
    1 tsp crushed thyme
    1 tsp salt
    2 tbsp brown sugar
    .75 tsp ground black pepper
    .25 tsp red pepper flakes
    .25 tsp nutmeg
    .25 tsp cayenne pepper
    Here are a few other ingredients from the original recipe.. you can add them or you can not.. its your choice..

    .25 tsp coriander
    1/4 cup maple syrup
    .5 tsp paprika

    1/4 cup Powdered Milk per 1 pound of meat (in my case, I had 7 pounds, so that was 3/4 of a cup).

    once you cook them and smoke them.. you can use a sousvede cooking unit.. then you know they are at the proper temperature.. then cold smoke them .. like you would cheese..
    as for your air well.. here is a four stage reverse osmosis filter..

        • re: The Great Dycktator, 1940
          feat: Charlie Chaplin


          I’m sorry, but apparently retaining a silent “k” as well as “y” for “i” may be a quaint throwback to more simple times to our cherished friend from an original colony.

          Speaking of bygone eras, today a great-great-great grandson of England’s King GeorgeIII, King Felipe VI of Spain and his wife met the Servant of the People at the Royal Palace in Madrid. The dapper King along with a formally attired Queen Letizia perhaps were exchanging knowing matrimonial smiles as they motioned their guest as with invisible strings to stand upon the “X” in preparation for their photo-op. President Zelensky rocked his olive t-shirt emblazoned with a flag of Ukraine on its shortsleeves. No iron cargo slacks segued into a platformed pair of trainers sporting matching shoelaces. The Royal Couple also introduced the esteemed visitor to their Defence Minister elected under the Spanish Socialist Workers’ Party banner, The Most Excellent Margarita Robles-Fernández, OSRP (Grand Cross of the Order of Saint Raymond of Peñafort). Apparently St. Peñafort compiled the canons which ruled the Vatican’s faithful from the 1230’s until 1917.

          One understands from msm reports that Mr. Zelensky brought grateful tidings for Spain’s gifting Patriot missiles while expressing regret that he had no platform from which to fire them.

          Published images of the grand quartet would suggest the tête-a-tête took place in the Palace Throne Room. Unlike ceiling-fixed, solar-driven exhaust fans of East Texas, the Palace’s lofty ceiling height incorporates the famous fresco The Apotheosis of the Spanish Monarchy from the 1760’s by the Venetian painter Tiepolo. While the King may have purviewed his continents from fresco above, there was no official Kissing of the Hand ceremony.



      Brown Sugar Maple Sausage Seasoning 2lbs is made with salt, spices, brown sugar, maple oil {natural and artificial), and less than 2% silicon dioxide added to prevent caking.

      Recommend Casings

      Natural Hog Casings 35-38mm
      Pretubed Natural Hog Casings 35-38mm
      Ready to Use
      Because the sausage seasoning comes pre-blended, it saves you time and effort of mixing the ingredients themselves. No additional salt needed. Store in cool dry space.

      Net weight: 28 oz. (2 lbs.)

      With that last line, they lost me as a potential customer.

      The only thing worse [in food quantity marketing] than shrinkflation is shrinking the contents, THEN LYING ABOUT IT!

  4. Great magnolia blossoms, George, and Elaine has a beautiful face. And nice skin. I lived in Atlanta in the early 1980’s, so I do remember magnolia trees and red bud trees. Here in New Mexico, the cholla cactuses are sporting their magenta flowers, and the claret cup cactuses are showing off their red blooms. Since we did not receive much in the way of spring rains, it is now fire season in our state, with several active fires burning. It would not surprise me if the Forest Service shuts down areas in the state until our monsoons arrive in July.

    • I will pass it along to Elaine – all these red lights, vitamins, and outdoors pays off, I guess?
      Hope you don’t get fires this year – memory is a dangerous thing but didn’t you say maybe 5-10 years back you were in the hills of ABQ? Not nice terrain for wildfires…

      • George,

        My house is in the East Mountain Area near the local ski area. It is situated at just about 7,000feet in elevation, east of Albuquerque and south of Santa Fe. Been here since 1987.

  5. George
    I have one just like this in my attic to drain away the condensate.
    Instead of hose to bucket to pump to another hose with check valve just stick the hose into the condensate pump, run second hose outside and and power up.
    Also two beautiful flowers!
    My mother and her sister both were known by their use of mass quantities of “Jungle Gardenia” perfume. Still a beautiful odor.
    Happy Memorial Day.

    • (God I miss Marketing-Engineering meetings, Al!)

      OK, but the spec here was:
      1. The condensate drain must be lower than 13 inches, or the condensate will not flow out of the a//c unit.
      2. The water head on the water barrel is about 39 inches.
      3. Without a check valve you would still have a water column problem.
      4. And the proposed solution doesn’t run on solar.
      5. And (the key marketing spec) is that we can’t just run the water on the ground, we want to recylce it for watering the greenhouse.

      BTW you will be thrilled to know that after 3 x watering on Sunday, overnight the entire 2X50 gallon water barrels were full of water again, so we are at least hitting spec on performance…
      Tell me how to get from a 13″ condensate to a 39″ head and not backflow. You high rollers with houses that have roofs and aren’t recapturing water, well, you’re lucky – let’s put it that way.

      • Hadn’t thought about mine being in the attic, so I have enough siphon that it is never a problem. The hose goes from the attic pipe trace down to the basement, then along basement ceiling out the wall to the yard in back. I have thought about adding water catchment from the gutters, but hadn’t though about the AC condensate. We get enough rain here (48-60″/yr) that you would think the AC would be an afterthought but we are humid enough that it would be a considerable amount. The line from the Basement 2.5 ton unit was plugged for a while, and before I got it unplugged it filled a 5Gal/week so it is considerable.

        • You might think about it Al – the atic unit may put out 2-3 gallons per day – and that will water a small patch of standup planters like in our greenhouse…

      • “Tell me how to get from a 13? condensate to a 39? head and not backflow.”

        Place the A/C on a shelf, above the barrels…

  6. George
    I have one of these in the attic for the upstairs unit. The basement unit drains into the french drain around the foundation.
    Also, Two beautiful flowers this morning.
    My mother and her sister were both known for use of mass quantities of “Jungle Gardenia” perfume. still remember that fragrance every summer.

  7. George, why the excess complexity?

    Why not do the obvious and elevate the A/C unit and simply let gravity drain the water outside somewhere? Bilge pumps, buckets, check valves, wiring, etc., just seem to defeat the KISS principle! Why Rube Goldberg it if not necessary? Perhaps it’s all prep for writing the column…

    Today I need to elevate a car and check the brakes, possibly replacing pads or shoes as necessary. Simple enough, but it takes time. I can’t complain – my vehicles require very little maintenance, but it’s worth doing what really is necessary. Upcharging the A/C on two cars too, since it’s about to get hot again. At least inside it’s comfortable without heating or cooling. Two necessary tools for quick and easy work – a good floor jack and a powerful cordless impact wrench! Of course, a concrete floor helps too.

    • more link clicking and I saw this,,,
      “ConditionLooks and functions as if it were new. Minor packaging damage observed during inspection.
      Sold byAmazon Warehouse”

      I’ve seen some weird stuff written by Chinese translations into English,,, this reminds me of those experiences.
      or it could just be a seller or Amazon employee using a menu drop down selection
      When it comes from Amazon, who the hell knows

    • Twice through a coffee filter and add some Red #2?

      I don’t trust Dex/Merc, prefer to get the individual Dexron and Type “A” (and those odd blends Chrysler uses.) I dropped $1400 on a trans rebuild a few years back, because I used a universal fluid instead of the specific one called for, and I’m in serious need of a Turbo 350 rebuild, likely from a fluid problem. Fluke or issue? I dunno, but I am not willing to do a double-blind at my expense, to find out. Type-specific fluid tends to be cheaper anyway, although sometimes harder to find…

      • Ray, this is for a Saturn TAAT transmission. It’s a highly reliable unit if you understand it, and it simply wants Dexron III, not Dexron VI which is the currently available product. Other than that, it’s rather tolerant, though the original valve bodies and solenoids are the weak spots. I’ve never seen a clutch pack in one fail, nor been unable to fix one. The more modern fluid seems to have a lower viscosity, though it’s touted as compatible.

        I just thought the ad on Amazon was rather idiotically funny, though I’m not sufficiently interested to order the “used” fluid.

  8. “ShopTalk: Instrumentation of Tomatoes!”  as we pull the night shades over the monitor to hide it…”

    (Chuckle). I wonder how many people ‘got’ that pun. Tomatoes are nightshades family.

    My crippled old Magnolia is not much more that a crooked stick maybe 1/4 the volume of yours. But it’s blooming, too. But not THOSE Texas sized blooms. And Elaine has it properly on the Left side of the head, to signify she is ‘taken’. Blooms on the Right ear means it is all ‘right’ to fool around! Old Hawaiian tradition.

    Yeah, the Gardenia bushes are smelling up the front yard, too. Mine have a species of tiny white orchids on long strings that bloom several times a year, but only last about two days. I call them “popcorn orchids” because the long strings of them look like popcorn strings you hang on a Christmas tree. Spring has sprung in the tropics.

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