Backyard Globalization
An Aquaponics Greenhouse
If we face some simple facts:
- food prices will rise,
- chemicals sprayed on crops are generally bad for us (and pretty much everything else but the genetically engineered plants they protect),
- the transportation of food creates a lot of negative environmental effects and lowers food quality.
Then, we need to define a plan of action to eat better, and eat sustainably.
Why Aquaponics?
To Dirt, or Not to Dirt
Hey, plants grow in dirt - everyone knows that. So this might seem like a dumb question. It would be without a doubt easier to try and grow enough food for 2 in dirt, if I had enough of it, and enough time to do it. Like most people - I don't.
We have a normal city lot, partly covered with the house, driveway and garage, with the typical grassy bits in the front and back. Even if we bulldozed our garage and plowed the dirt underneath, I don't have anywhere near the quarter acre per person needed to grow enough produce to feed myself and family.
More importantly - I am not a farmer, and can't spend most of my time growing crops. A lot of land to work takes a lot of time to work it.
Lastly, in soil I would need to use many of the same fertilizers and insecticides that coats our food from the store - so while better, not as good as I am hoping for. Depleting and building soil requires chemicals and creates waste.
Hydroponics has some advantages, like planting density can be much higher, yields can be faster and greater, and there is a lot less bending over! Still, chemicals are needed, water becomes toxic and waste is created.
In aquaculture (the farming of fish), there are some similar problems, like toxic water waste.
Aquaponics uses naturally occurring bacteria to break down fish waste into plant food. The plants extract the food from the water, and the water goes back to the fish in a recirculating system. So inputs are fish fingerlings and seeds or sprouts, and water. The output is food, fish and very little else.
Pros:
- Greater yield per plant
- Higher plant density
- No chemical fertilizers or pesticides can be used (they kill the fish)
- Suited to indoor and outdoor use
- Can produce year-round
Cons:
- Complex system
- Higher initial investment cost
- Requires electricity (typically)
Well, I enjoy complexity, can DIY a lot of things to keep my costs down, and use solar to power my needs since we get a lot of sun in San Jose.
So, for veggies and greens, I will go soil-less. The trees are mostly going to go in to the ground, but we will put a tree into a container that will get incorporated into the system, and also grow some plants vertically in a compost drip system.
Why a Greenhouse?
Control and Balance
I need to eat all year, so the system needs to produce food all year. We have a lot of time to grow outdoors in California, but it gets both very hot and can freeze here. We actually don't get a lot of time to grow things like cilantro or lettuce, these guys race fast when it heats up here.
Maximum food from minimum effort in a small footprint will be much easier in an enclosure. The birds, squirrels, raccoons, possum, and bugs already eat well across the rest of my yard.
Most plants will grow well in the 70-75 degree range, but I will be incorporating fish in tanks, and need more stringent control over the water temperature. Since that's also the water for the plants, I need to make sure it's not going to burn them or stunt them.
Humidity, light, light spectrum, air CO2 levels, water dissolved oxygen, flow rate, PH, and more must be kept in balance to meet the needs of the fish as well as the plants.
A larger system would be more resilient, and 500 square feet would be plenty in an outdoor system. that means building out my front yard, or replacing my garage, or not doing that. Also, a system that size would be more than an hour to maintain each day, and produce more food than we can eat.
In 500 square feet, I could readily create a food business, both selling greens and feeding my family. Getting up early for farmer's markets is not my cup of tea.
80 x 80 x 88 Inches of Food
Flexibility, Maintainability, and Interoperability
Wanting to easily and sustainably grow food isn't a new or unique idea. More healthy people doing healthier things for the environment is either a nice idea to maybe even required for our ongoing survival. The current agribusiness trend in the US is having a lot of negative impacts, and we should take some personal responsibility and make some changes.
This size of 80 x 80 x 88" directly reflects that goal. This means more than one can be loaded into a shipping container, can be delivered, transported and warehoused like a POD, will fit on any driveway - or even patio's balconies and rooftops. Pallet-sized will not produce enough food, and the size of a shipping container (equal to about 1/4 acre of farmland) is too big and produces too much food.
It wasn't that long ago that most people ate very locally. Automobiles and modern agribusiness have changed that a lot, at great toll to the environment - and many of the crops involved became less healthy. But we can leverage their strengths, while getting back to a more successful model.
Maybe you have your own kitchen garden, or some room in your potting shed, and aren't getting year round food. Maybe you are Chinese, and see the magic in the math. Maybe I am wrong, and I will not be able to get it down to this size.
But, we will target this size because it makes having a billion of these things around on the planet a lot more feasible.
We will also target 100% solar power, and water input of less than 2 gallons per day (or just a bit more than a single toilet flush).
Green Food Aspirations
Watching What We Eat
Most of the time, a grocery list is forgotten about as soon as you leave the store with the goods. They reflect what we are eating and buying, rather than what we would hope to. Good data to use in a plan to build a greenhouse to grow what we eat.
It took little time to come up with a list of over 3 dozen things we regularly eat that could come from a greenhouse. Plus a second list of produce that should not, mostly due to space. As awesome as it would be to have a mangrove in there, I am going to have to prioritize.
As I do more research, I find more and more people growing all sorts of different things without soil, all over the world. This will change what we grow, and I need to plan for some space to try out new things. I also plan on growing duckweed to feed the fish, so lets say we are looking at 40 things in 80 x 80 inches. Seems a bit crazy, even after having made the choice to go primarily soil-less.
That doesn't mean all the plants would be grown in the same way, or having a huge space dedicated to DWC (deep-water culture) methods. Media bins filled with expanded clay pebbles will also provide better nutrient conversion in the system, and a better way to grow things like turmeric and carrots than DWC.
NFT (nutrient film technique) will also allow me to grow things like sprouts, baby salad greens, and some herbs like cilantro at a very high rate and in minimal space. We will have four types of grow systems inside: fish, media bins, DWC, and NFT. I'm going to try four different NFT systems. NASAs use of solar-powered ultrasonic foggers (operating in space) is also the basis for one of the world's largest indoor farms. I will go into the four types I'm pursuing and why I will try them in my next article.
Keeping track of the produce we are eating has already started causing us to eat more greens, and just working on the plan is already having benefits :)
Little Bits of Water
Soil-less Growing Saves Water
Everything I read offers the continual promise that soil-less growing will save water as compared to conventional soil based growing.
How much water? Different claims of 70% to over 95% abound. I will build a solar water purifier at some point, that will allow me to track the water consumed. But lets look at the 4 models we will try and what to expect with each of them.
The first components will be extremely simple, and I will compare them to my neighbor who is growing lovely greens in her yard. She has a 5 x 8' garden, and waters 3 times a week for about 10 minutes. Standard flow rates for a hose are 9-17 GPM. With the sprinkler head, we will take a simple value on the low end of the range. Assuming her hose is putting out about 10 gallons of water per minute, we get ~300 gallons per week for 40 square feet. 7.5 gallons of water per week per square foot seems like a lot more than when you're standing there with the watering hose.
In contrast, microgreens in standard 10 x 20" trays without water movement or drainage "should" come in at 95% less water usage. I can't eat the product of 40 square feet of microgreens, I will start with 7 square feet using this very basic grow method in the bread rack prototype (more later).
This method uses only purified water, and no other inputs than seeds and water. It is often referred to as Pure, or Clean, since it uses no organic fertilizers or chemicals of any kind. It is beyond compliant with Green or Organic labeling. The seeds are spread on a grow mat, often made of coconut husk, hemp, or other organic fibers, the mat sits in the tray, and is kept wet. If I can grow a crop to edible maturity for a half gallon of water, I will have achieved a 95% water savings vs soil in this method.
The second test started on Monday, Cilantro with the Kratky Method. I run out of Cilantro every week, this was a high priority test! The seeds should sprout by the end of the week, and the plant will be relocated to the bread rack prototype. This is another extremely low water consumption method, which promises larger harvests in less time.
A continuous flow NFT system requires pumps, hoses, and a plan in 5 dimensions. Evaporation will become a larger factor, and monitoring and management component requirements explode. This is where electrical engineering, mechanical engineering, hydro-engineering, and taking on some engineering methods are required. Plus some PVC and a few tools I don't have yet.
Adding a fogponics component at that stage should be very little extra work, and seems to offer the best growth rates for the least water. Using ultrasonics to create a fog of half-micron water particulates that flow around the plant roots will also require more atmospheric monitors and management components. As well as more research time on the NASA site.
These 4 types of NFT systems will need some testing and prototyping. Building electronics prototypes often starts with bread board. My format is bigger, and has some organic components, but I need a standardized, cheap, and flexible substrate - like a commercial 20-shelf Bread Rack.
Bread Board Bread Rack
Used. Free. Up-cycling. Yay!
A standard commercial Bakery Rack is easy to come by at a restaurant supply store, or quick delivery from a host of online sources. Standardized sized makes for a lot of mass produced options, and I happened to get one for free last week. Fortuitous coincidence?
Free of dollars, but not time. This one was abandoned on the sidewalk a block from here, with a big free sign taped to it. After staring at it for a few seconds, casters... I tied the dog leash to it and pushed it home (with my helper who got the rest of her walk after).
So, it's bowed out in the middle, it's dirty, with bits of tape and labels all over it. But, it will bear my weight while rolling, has 7 plastic trays, and delivery was free ;) Onto solving it's basic problems.
Something very heavy has been placed on top. At the center, the rack is 1 1/8" wider than at the top and bottom. It has been used for a non-food purpose. Lying it on it's side across a pair of 2 x 4's I can put something very heavy on top to compress it. I'm not going to heat the steel, so it will need to be heavier than I can lift. I put another pair of 2 x 4's across the top, and an empty 25 gallon water storage tub. I add water until the center of the rack is 9/16"s narrower than the top and bottom, and leave it for a day. After siphoning the water off into my lawn I find I have gotten halfway there. After a flip, and another 24 hours with the tub full again the bow is gone. After a pressure wash the grime and labels are gone. With a wire brush head in my cordless drill, all the surfaces are stripped to eliminate any remaining residue from the steel. This will work just fine.
Just like the bread board I can move my components around in this modular grid. Adding pieces on, and even clipping out some I don't need. A 20 dollar plastic food grade cover creates the right environment to keep food safe and clean. Pow - a mobile greenhouse prototype - check. Ready in time for the Kratky Cilantro? No...
Lighting is so complex I would prefer to start with it later, but it is October and I have 3 weeks before rainy season starts. The rolling rack will make it easy to have outdoors on nicer days, and stay in the garage on stormy ones. Eventually the automated version should manage the amount and type of lights the plants are getting internally and from the sun. For prototype and test I have opted for a T5 full spectrum 2 x 3' fixture for the inside of the garage for external, and a set of 6 LED lighting tubes (red/blue grow spectrum) to use within the rack itself.
When I worked in the IT infrastructure industry, I also physically managed my own teams rack of hardware. Managing IT, someone on my team did this. Managing documentation and writers, I did this myself. Funny how all these things are coming together.
The rest of the materials for the Clean microgreens experiments are:
5 1020 grow trays with domes,
1 10-pack of coconut fiber mats,
1 temperature monitor with power controller,
5 heating mats,
1 power strip with integrated timer,
1 gallon of distilled water,
and a 5lb bag of microgreens seed mix.
If I spend 10 minutes each day seeding one half sheet and watering, is it really going to create a salad a day cycle? Expecting 10 days to mature, on day 11 I should be able to eat what I planted on day 1, and use the same space to plant again.
If it works, that will have some very good implications for our overall size goal, since 9 of these racks would fit into an 80 x 80 x 88" greenhouse. Producing 5 square feet of microgreens daily is a commercial amount (It sells for about $10 for a 5 x 7" piece in my area) but I want some space for other veggies that will do more than round out my salad.
Lastly, I'm using local control for thermal management. You should tell me not to do that. I will tell you why I did.
Next time.
Reducing 1500 Miles to 15 Steps
Almost 2 weeks ago, I began this simple project in my garage, with a free bread rack and some horticultural supplies from Amazon. Months of research went into action, but I wasn't sure it would work.
I prepped the first seeding tray by cleaning everything and soaking the jute fiber pad in water overnight. Just 50 mg of the seed mix is all it takes to thinly coat the pad, and then spraying it with water twice a day also took about 10 minutes of work.
Nine days in, the experiments are feeding us. After 4 days in the dark under a humidity dome, I moved the first tray of microgreens under the LED lighting. At this point I also planted another seeding tray, a scallion trimming and some basil seeds. Nine days in the baby trees arrived in the mail. I have to say it lifted my heart to unwrap them and put them into the baking rack. Delightful tree babies in a bit of shock from their trip through the mail.
As more seeds were planted, more piece of the system needed to be wired together. The seeding trays and pots sit on plant heating mats. A temperature probe and simple power controller are providing a consistent 72 degree Fahrenheit water reservoir for each plant. Regardless of the temperature in the garage, the rooting area of the plants is always ~72 degrees.
I use the bottom shelf for germination, and growing seedlings. Since the seeds on the jute pads are not covered by soil, I need to keep them warm, dark and moist for the first few days, since they are not in soil, I wrapped the bottom shelf area with black agricultural plastic, and clip a dish towel to the front to create a positive seeding environment. Today tomatoes and chocolate basil were started with the next tray of microgreens.
The middle shelf has the microgreens that are growing, but not yet ready to eat. I Also have cilantro, scallion, and a sad houseplant my wife asked me to revive in there. It's quick and easy to spray down the tray of greens, the cilantro is in a wicking pot, so I only need to add water 1-2 times a week, and the scallion just gets sprayed with the mister, it's just growing in rocks.
There is about a cup of soil being used here on this shelf. Sitting atop expanded clay pebbles in a mesh with wicks down into their on water supplies. Small amounts of composted soils in different parts of the system will provide a valuable habitat for bacteria and new sources of nutrients.
The top shelf is now lit by both the T5 fluorescent fixture, I also have an LED lamp suspended close to the greens that I seeded 11 days ago. Healthy from the lights and the water from the ultrasonic emitter above. Today they were on the menu for dinner, and I couldn't resist just snacking from it while tending to my rack garden.
Greens in rotation seems to have been a resounding success. In less than 2 weeks, I am eating the results. We are going to be eating the tray of greens that are ready for a few days, without them spoiling on the grocery shelf or in our refrigerator. Fresh on my sandwich, in my dinner, and as a snack. In 4 days I will seed, and re-rack the trays so that the newly germinated seeds move up into the light, and the ready to eat tray replaces the one we have been eating.
Eating - Growing - Germinating - Planting
It takes just a couple of minutes each day to keep this going, but that is also because I thy to build in as much automation in each layer as I can. Each shelf has the temperature controlled mats set to 72 degrees. I went for local temperature control for 2 main reasons:
1. I did not need to heat all locations initially, and likely that will become true again as things move around.
2. I want the opportunity to control things both at the unit and enclosure level.
Heating and lighting are fully automated, watering is partially automated. Since fish will come later there are a few more sud-systems to build out before this can to go much further. The top shelf is now automatically watered by water vapor, and each of the plants growing there also has there own reservoir. When the heat sensor turns on the tray heaters, it also turns on the ultrasonic emitter dumping a small amount of water vapor on to the plans below. Pointlessly for now - also into the pot where the tomatoes will be transplanted next week.
In the morning, the lights come on, I come and spritz for a few minutes, and I'm done. In the evening, I have some task like soak a pad for planting tomorrow, move a tray or have some thing to easily do - and now a little crunchy treat to enjoy while doing it. The water vapor dropping on the plants with the red-blue LED lighting is also mesmerizing sight.
I will post a 2 week update, but so far I am amazed by the results. The average meal has traveled 1500 miles before we eat it here in the US. My salad machine is online in 12 days. This piece of my diet now travels 15 steps.
Failures, Successes and Refining Expectations
Some experiments have problems, some fail. Sometimes you can be surprised how having a sick baby tree can make you feel...
Not having had a green thumb, understanding why plants are unhappy is a lot to learn about. Understanding why I was unhappy was pretty simple, the Moringa plant was looking pretty terrible. Finally, I shot a detail pic of the spots I could see on the leaves, so unlike these old eyes I could zoom in. Spider mites. Ugh.
I spoke to a former greenhouse manager - she laughed at me. "You didn't quarantine the new plants when they came in?" No, and I had exposed the rest of the plants near it to the parasitic mites. The closest plant - the Neem tree. Well, Neem is immune to spider mites and Neem oil is used as a natural pesticide. If this tree was bigger I could be using it to cure the Moringa, but it's big enough to take care of itself!
A few drops of Palmolive dish soap and peppermint oil mixed in to my water spritzer cured the mites, but not before all the leaves fell off the quarantined plant. I left its bare stick of a stem in it's pot to solve another problem that had come up, leaf spots!
It's also getting colder here in the garage, and until now most of the plants spend much of their time under a dome. Eventually I will be transplanting the tomato and basil sprouts into 4" pots, from the seeding domes. The bakers rack is convenient in another way, a transparent cover is on the way for > $20. Zips over the frame for keeping pastries and breads fresh. Pow, instant enclosure. Now I can see if the seeding mats keep the ambient temperature warm enough inside and monkey with the fogger.
The ultrasonic water vaporizer I have been using to add humidity is not working. It's on for too long at a time. I'm getting a few leaf spots on the Neem and too much water is building between the stalks on the top rack of microgreens. With the cover coming for the rack, I'm taking this offline for now. The uncovered green trays radiate humidity. That should be enough when I get the cover on.
We're also not used to eating this many greens, but they also make a tasty snack as I work on the rack. Just being right there... It hardly makes a dent. If one tray of microgreens is more than we can eat in 4 days - which is how long they are ready for - what will I do then?
UPDATED: The rack cover arrived and while the sides are clear the top is white! While this is probably fine at the bakery, it's going to block too much light for me to hand=g the light above the rack. So, I have turned one of the extra shelves upside down as a lighting hood and put the cover over the whole thing. None of the lights get very hot, this should be enough to help out during the day to keep the enclosure warmer inside.
PH and Moisture
Most of the nutrients for plants in an aquaponics system comes from the fish. Since there's no fish yet, adding nutrients to the water is essential.
Most plants do best with a PH in the 6-7 range. Different soil mixtures can have a more base or alkaline PH. I have a volunteer raspberry coming up in the corner of my yard. Making the soil around it more alkaline will help it grow, but this is not the case for most of the plans I hope to grow and eat.
Fish can get sick or die if the water PH becomes a problem for them. I don't want to kill off a lot of fish, so planning to manage this carefully is a must before incorporating them. They will also need better temperature management than I have so far.
A cheap PH meter will allow me to measure the PH of the water I am putting in. A reusable electric meter will be a better solution than an limited use chemical kit at this point. Conveniently they also come in kits with Electrical Conductivity meters. The EC meter will measure dissolved solids in the water. Again, something we need to care about for fish, and also to determine the level of nutrients that have dissolved in the water.
I'm using an inline carbon filter, and if that doesn't turn out to be enough I can start distilling it. The filtered water I'm using has an initial PH of just over 6 which is great. However, the water is heavily mineralized, even after filtering the ppm is over 440. So when measuring how much nutrient I have added I will need to subtract 440, but this also means I need to go a bit lighter since there is a lot in the water already.
The other main factor is the grow media. Two of the basil tests are going in wicking pots in potting soil. The other 2 are in coir fiber, which is PH neutral like the fiber pads used for growing the microgreens. Two varietals of basil, in 2 different grow media in 2 different shapes of pots have been going for a couple of weeks now. The chocolate basil in soil over expanded clay pebbles is the clear winner from this test.
It's very easy to maintain the PH of 6, since most of the plants are growing in coconut fiber or on a fiber mat. The expanded clay pebbles are also PH neutral, the first few trays of microgreens have demonstrated a consistent PH the whole cycle.
Nutrients and Watering
Starting with fish and then adding plants probably would have allowed me to keep out of the additives game. After growing 3 trays of microgreens in the Clean method (just seeds and water) I've mixed up a standard hydroponic nutrient mix of:
- 6g Epsom Salt
- 20g Calcium Nitrate
- 20g Masterblend (4-18-38)
- 8L filtered water
Spraying the trays down with about 3 cups of water twice a day consumes most of this. Everything else I am growing needs a quarter cup or less of water per day. I don't spray the basil, instead I refill their water reservoir twice a week. So far, 95% of the water and effort are going into the microgreens. To be fair, that's all we can eat from this as of yet.
Daily maintenance, soak the greens that are germinating on the bottom rack twice a day.
Check the germinating beans and basil, top up water reservoirs as needed.
Check the greens tray on the center rack, spay the edges of the pad if it's looking dry, top up the reservoir as needed.
Check the basil and tomato sprouts, these keep their water pretty well in the domes.
Eat some greens from the tray on the top rack, check it's reservoir, fret over the recovering Moringa. (the stick grew 3 new branches from the top, hoping it will recover from the mites)
With 3 trays going, water consumption has gone up to 8-9 liters of water per week. About 95% of that is going into the microgreens. It ramped up really quickly, but I get to put greens into everything right now.
Continuous Microgreen Abundance
Wow, this is a lot of greens!
The next batch with the nutrients added is nearly 40% taller than the previous batch that used pure water. Three trays in 3 stages, rotating between the 3 racks produces a super-abundance of microgreens.
Microgreens Growing Recipe
The greens in the bottom rack germinate under the humidity dome in the dark for 4 days. I top-water, spraying them down to soak them and the fiber pad every morning and evening. After 4 days they are moved to the center rack.
The greens in the center rack are exposed to the grow lights for 12 hours a day for 4 days. I keep spraying for the first 2 days, replacing the dome each time. After these 2 more days the greens have grown too tall to easily pop the dome on and off. So I leave the dome on, and just check to see that the reservoir has enough water each day.
On day 9, these are ready. I move them to the top rack, remove the dome and spray them one last time. They are perfect for the next 4 days, I might top up the water at this point, but otherwise, I am just trimming them off with a scissors and eating them.
After 5 days in the top rack, these are getting a bit sad, so we're on a clock both to eat them and to replant the tray.
Cadence
Every 4 days, you are seeding a tray to germinate, moving the germinated sprouts to the light, and removing the grown sprouts dome for final grow-out and consumption. The day before that you finish your harvesting, and soak a new fiber pad overnight to seed the following day.
I'm mixing up 4 liters of nutrient solution about twice a week. Although the plants are on warm mats, and the lighting is automated, it takes a few minutes to spray each tray. The microgreens are eating about 95% of the effort in the rack, as well as 95% of the water consumed. It's significantly less water than growing the greens traditionally would have been - .5 gallon per tray per day, I need to automate watering this to bring the effort down on the microgreens.
Maybe, grow less of them as well, until I learn about more things I could be doing with them. They have been great mixed into my mulligatawny soup, with a little Dukkah and dried scallions on top. Yum.
Environmental Automation for the Greenhouse
With the tomato plants getting bigger, and my quest to make this Moringa happy again, it's time to add another layer of thermal management. It's winter, and my garage is a cold place after all.
Also, there is no wind or other stimulation of the plants to grow more robustly. Yes, you can rub them all the time, but that's not going to work out every day.
In the first phase, sprouts and seedlings mostly in domes were easily heated by the seeding mats on each of the racks. The root zone is kept at a stable 72 degrees Fahrenheit.
The grow zone is not, and we have freezing temperatures overnight while the lights are off and not adding their small amount of ambient heat. Instead of reversing the grow cycle, and running the lights at night, I will add a heating element and a controller that can also control a cooling element in a few months when it warms back up.
This controller is more sophisticated than the controller used for the seeding mats, it also has a probe, but will power on and off both heating and cooling devices. The probe for the seeding mats goes into the water reservoir tray on the bottom rack, this probe is suspended in the middle of the top rack b the crowns of the tomato plants. With a 100W ceramic heater set to go on when the rack falls below 48 degrees Fahrenheit. I'll plug a 6" box fan into the cooling circuit when it gets warm, if I have not moved into a bigger format by then.
Disruption is Required
To develop strong plants that can handle the weight of fruiting, the stillness of the rack needs to be disrupted. I think this will also help me in my problem with the ultrasonic fogger. An outlet timer, with a short interval timer should do this a lot better than when I had the fogger run whenever the seeding tray heaters ran. By putting it on this timer with a 6" clip on fan., I can create vapor and wind for 2 minutes every 4-6 hours. I'll start with every 6 hours for now and see how it goes.
Analog vs Digital
If you are in pain reading about these fixed timers, analog power switching, lack of logging capability, remote access, and lack of a better user experience than 2 little temperature displays - I have some bad news.
I haven't even ordered an Arduino R3 yet.
Simply - the best digital experiences are supported by an analog infrastructure. When the system is more sophisticated, I will naturally have to evolve a digital architecture. Do I want to be able to see my plants and change their conditions even while on a trip? You bet.
Testing code works a lot better when you can do a thing without it as well. These analog components will continue to be useful after I start pulling together sensor code, and I'll be prototyping something else by then.
I've bookmarked some Github repo's linked from a couple of projects on instructables.com, greenhouse automation, hydroponics and even a little in the way of aquaponics projects are available. I haven't opened Eclipse in a long time. It will be some weeks yet before I have to go look for some new libraries and updates when I knock the dust off it's icon.
Why Didn't I Do This Sooner?
A lot of greens have come to the table, starting this week cilantro as well, and I wonder why I didn't start doing this sooner.
Instead of another tray of microgreens, I have started a tray of other plants this week. I picked 10 plants to start, based on what we eat a lot of and are suitable to grow hydroponically, and one I just wanted to try out. 4 liters of water and a compressed block of coir fluffed up in a few minutes. I spread it into 1" seeding trays - these fit in the same 10x20 trays as the microgreens, but I am using these 1" cell inserts instead of the microgreens tray and a fiber pad.
Looks like dirt in there? Well, it's coconut coir fiber which is PH neutral, and completely sustainable. Peat is PH negative, and non-renewable. We have a lot less bogs around, and we have harvested a lot of peat already. We're steering clear of peat.
This means we are growing these seedlings hydroponically - all their nutrients will come from in the water, none come from the 'soil' since the coir is just there to support them. These seedlings will be ready to transplant into a hydroponic or aquaponic system directly. If had I used planting mix to start them I would need to disturb them by washing away all that soil soil. That should save a lot of work in a few weeks. Until then I can supply a steady PH and temperature, and consistent nutrients in the same hydroponic mix as everything else.
As with the tomatoes, I have planted more seeds than I plan to grow to maturity. Plants that don't start well will get weeded out, and the most robust plants will be transplanted as they get big enough.
Yellow Onions, Red Onions, Scallions, Bok Choy, Broccoli, Red Cabbage, are highly used in our weekly cooking, and I'm adding Strawberry Spinach, Borage, Nasturtium, and Calendula to that.
Seems like the heat is working a lot better in there. Logging temperature readings becomes more desirable every week. I'm going to need to select a commercial greenhouse to keep things simple, rather than more straight into a 80' custom enclosure. I just planted 72 plants, we need to grow.
Underground Dilemma
Carrots, turmeric, daikon radish, and ginger are going to be a different challenge than the leafy greens and fruiting plants growing in the rack. Turmeric is on the way, hopefully some of it will be ready to sprout.
I've had potatoes growing for three years in a planting box with mulch and compost. This is the easiest plant to grow, maybe ever. Any funky, wrinkly, sprouting old tomatoes you have forgotten about are the perfect place to start. Throw those in a big container of whatever dirt, compost, mulch is handy, water it and put it in a sunny spot.
I sometimes water it, but more often forget to. I let the squirrels and other critters make a mess in there, it sits ignored until it has grown out and then withers. Right now they are burgeoning, looking great, and when all that leafy greenness does away, I pull out the potatoes I want to eat, mix the remaining rhizome with some new compost or mulch and dump it back in the planting box.
Water nearly never, and harvest it when it looks dead. Love potatoes.
I will start growing other root veggies in 18' deep bins filled with expanded clay pebbles, with a flood and drain system and see how that works. I have read a lot of wildly different reports on this from others. Carrots were almost as simple as potatoes, and quick to grow. These don't seem to be a popular crop with other hydroponic growers. I have a feeling I am going to find out why.
Getting Into Greenhouse Debt
Today we welcomed a new friend, and with it the strong need to scale our grow infrastructure.
Amazing how many live plants are available on Amazon, today's delivery was a purple passionfruit vine. Year-round passionfruit? Yes please!
Having learned my lesson with the Moringa, we did a thorough once over, and the vine will sit in quarantine for 2 days. When it ramps up, this vine will grow up to a foot a day. That is way too much for the bakers rack. It's getting very crowded in there, even without any microgreens going.
I need to rearrange things this weekend and install the cooling fan. It's warming up to over 80 degrees inside the rack during the day, the tomatoes couldn't be happier! Before we get temperatures the 90's I need to finish the last step in automating thermal management. A standard computer tower fan, hooked up to the cooling circuit on the thermal monitor and controller will be a snap to put in while I have the top shelf cleared out.
The only thing left to automate is watering. As with the electrical, my analog approach contained a garden bed watering kit, with hoses, emitters, etc., an Orbitz watering timer, an inline charcoal water filter, and in my case a 60 gallon food-grade water barrel.
There are no water lines to my garage, nor will there be to a greenhouse. As we get closer to adding fish into the system, a good volume of water will be needed. The large thermal mass of the water will help to stabilize the temperature around it - perfect for inside a greenhouse.
This will be an enormous amount of fiddling with little bits of hose and sizing them for the way things are in the bakers rack means a lot of waste. A lot of pieces that will be the wrong length when we scale into a bigger enclosure. Much worse - doing it all twice.
This is a clear sign I need to get some other things done next. Plus, I need to do a better job at managing my greenhouse project backlog. Because at this point it will be more work to automate watering now, than build out the greenhouse. It will be very easy to move all the lighting and thermal pieces, and - it's going to be spring soon.
I've been looking at greenhouses for 6 months, and have elected to go with an 8 x 8' Grand Gardener II. An 80" x 80" custom would cost quite a bit and I haven't figured everything out yet. Sticking with widely available commercial products has been working well so far.
For the first time in this project I can't get something off of Amazon - they don't have this greenhouse available. In this case we're going with Walmart.com - they have a kit that includes the base, and will assemble it for me as well.
This will partially solve the problem of the seeding tray full of growing vegetable sprouts we started a few weeks ago, the growing sprouts will get a big area to grow in. After 15 months of research and looking at commercial and DIY systems, I'll be moving most of these seedlings into an Easy Garden, by MyGrowBot. It's a nearly autonomous hydroponic gardening table. For those who were sick of waiting for the Arduino to come into the picture, I saw some custom motherboard pics for this - however, I also ordered an automated Arduino-based watering system. I'll be extending it's code to cover more monitors and sub-systems after the big move into the greenhouse. Pump, hoses, relays, LCD, power supply, etc. with the code and the board.
That means a building a landing page for code here, as well as some step-by-step instruction pages on the other systems, and a lot more to come!
Greenhouse Infrastructure and Data Logging
The Greenhouse is assembled, and our friends at Walmart and Handy need to work on their API a bit :) I’m not one to throw stones, my technical debt has grown a lot with the size of my gardening space.
No plants have gone in yet, the first thing to go in is a monitor, so I could begin measuring the temperature and humidity. What happened in the greenhouse the first morning was a lot more dramatic than expected.
We will get to that. Let’s start with some what and why.
The greenhouse itself came last week on a pallet in 5 large boxes. Each box contained a small ocean of plastic parts. I had booked assembly as a service through Handy. Unfortunately the quote routed through Walmart was for 3 hours, which was only communicated to the installer. But, the installer didn’t know exactly what they were going to install. I knew exactly what was going to be installed, and had no idea the guy would arrive expecting to only be there for 3 hours...
Luckily, it was Friday and he was able to stay longer. We got the walls finished and the roof up, but it was well after dark and I had a lot of pieces to go. The solar system and environmental monitor arrived Monday, when assembly was “complete”.
Everything that comes with the basic greenhouse is done. The base is done, and I still have over 200 pieces to add. This package came with 2 automatically opening louvers. They will automatically open a side window and a top window when the temperature increases beyond their threshold. Pistons with oil that expands above growing temperatures push them open, and close them when it cools off.
These windows are both incomplete, like a normal development project - it’s done, but there are some features to be implemented :) The perfect chance to set a baseline before the water ballast and basic thermal automation is working!
For less than $15, you can get a small wireless monitor like the govee, which I set up yesterday at sunset to begin measuring a baseline. It was very easy to set up and pair, I am getting data, temperature over time graphs and alerts from the Mobile app. It runs on batteries, and transmits wirelessly. Very nice for the price.
So, of course after making coffee, I went to physically check the temperature data I had seen on my phone. It’s already 72. After a shower and walking the dog at the park I checked my phone and said to myself - that can’t be right, and went out to check again. Yes, the data on my phone was off, it only read 119, but it was 121 inside. A 50 degree rise in 90 minutes inside made it quite hot, and had reduced the humidity from over 30% to only 9%.
That would have been pretty hard on my seedlings and vegetable plants. A temperature increase of 50 degrees in an hour and a half would be pretty tough on us.
Complete with 2 features remaining means - unusable for purpose. Finishing the windows is required to move the plants in, so I had better go do that.
Moving into the Greenhouse
By looking at the data, it was clear the automated windows were mostly solving the problem. This alone reduced the amount of time the inside was reaching over 95 degrees to under an hour. Adding the plants themselves would have an impact, and filling the 60 gallon water barrel was going to have another one. The last big change is still pending - the hydroponic growing table has yet to arrive, I have left the entire south side open for it.
It was quick and easy to move most of the 5 dozen plans onto the shelves provided with the greenhouse. Then trellis the tomatoes and passion fruit vine, set up all the drip watering lines, and make sure they all worked without leaking. With the vents open and the doors open, I have rolled out a green carpet for the bugs and pests, so at this point everything got a good blast of Neem oil spray.
Spider mites have fallen deeply in love with the Moringa sapling, so I am hoping to start seeing some predatory mites on it - having a feast and helping it out. I have really grown to hate the spider mites over their love of this tree. If the predators need a boost, I'll get a bottle of predatory mites delivered and release them into the greenhouse, and my whole backyard.
With the drip irrigation lines all run, attaching the garden hose is easy so I can water manually while I get the watering system up and running.
I have the solar system up an running. A 10 x 12" panel outside stores power in the control unit I have mounted to the wall inside the greenhouse. 4 of the 5 USB power outlets are running to the lights I have attached to the inside of the roof and the front of the greenhouse. This has provided plenty of light for me to work in there after dark, but I am unconvinced it will be enough to supply the arduino continually.
The solar kit was $55, and the arduino based watering automation kit was $55, the latter coming with everything needed aside from an arduino. Which was perfect, since I want one with embedded wifi.
I'll need another pump, and a line pressure regulator, to get off the hose and onto the water supply in the greenhouse. Need to keep tabs on how often the plants need water in the greenhouse now, to establish how many watering zones I will need to set up.
My wife asked me if I was done now that the plants are in there. "No'" I laughed, "I am just getting started."
Small Greenhouse Watering Automation
Before we had a coronovirus lockdown, I was used to travelling a bit for work. Travelling for fun is good too, so we need to make sure the greenhouse can take care of most of what it needs by itself.
Temperature control has been working well enough for the time of year, but automating the watering is the critical next step.
A roll of drip irrigation tubing, a backflow valve, a blow off valve that connects to it, a short garden hose, a 25psi hose flow regulator and a 5' pump, along with a small bag of assorted connectors, and a few irrigation drippers and spikes take just a few hours to get working.
Manually testing the watering lines also show the Orbits timed valve leaks a bit with 25 psi pressure on it, so after flooding my plants instead of a quick watering, this piece comes out.
Now I have a small water container, inside is a 5' fountain pump pumping water up though a garden hose, into a 25 psi regulator, then the blow off valve, then the backflow valve, and then the 1/4" irrigation tubing runs to the spikes and the drippers.
A simple on/off timer turns the pump on for 2 minutes twice a day. All the plants are irrigated for 5 minutes each time, since the pressure created from activating the pump for 2 minutes runs the feeders for 5 minutes.
This feeds most of the plants, and has been working now for a few days so I feel safe in turning the physical lines over to an as-needed controller running from the arduino, rather than the timer based system. Yesterday it was hotter, and I needed to give the tomatoes a bit extra in the middle of the day. Watering based on soil moisture will be a big improvement
The other benefits of the water reservoir working like this is it limits how much water can be pumped, so a problem can't empty all the stored water through the irrigation system. I'm also made a rudimentary swamp cooler, with the temperature controlled switch and a small fan. If the internal temperature of the greenhouse exceeds 94 degrees, the fan blows air across the surface of the water.
The ultrasonic emitter sites in the same container, adding humidity to the air, and oxygen to the water 4 times/day.
The dog likes drinking from it too!
My GowBot has arrived, so I will see what impacts this has, and review what this does in my next post.
