Aquaponic Gardening, by D.P.

Aquaponic Gardening, by D.P.

This submission is about gardening (tips on what to grow and why) and how and why I am switching from outdoor to indoor gardening. I have been gardening since age 3 – much to the chagrin of my parents who, once they realized what was going on, quickly gave me my own 10 square feet with some lettuce and radish seeds and told me to tend to that in the future. I did get to take care of their garden as I grew older though. I also have had gardens on various soil types as my family moved about and so in many respects I am better prepped to grow (part of) my own food than most.

For many generations my ancestors, who lived in Europe, had small businesses and/or farms. In those days the grocery stores didn’t sell vegetables but just what we would call ‘dry goods’ today. People didn’t have much money so whatever they could grow themselves, they did in their own garden. They also didn’t have much in the way of weather forecasts beyond the type of clouds they happened to see and whether air pressure was rising or falling. To be successful in those days you needed to have a very different skill set than what most of us possess today. With respect to gardening it really came down to this: grow a wide variety of vegetable crops.

This tactic solved a number of problems:
– regardless of the weather there would always be a few crops that did well, so there was always something to eat.
– disease and pest control were iffy or non-existent, but again the chance that all crops failed due to them was small so there was always something
to eat.
– a lot of vegetables are high in specific minerals and/or vitamins.
Eating a variety of them was the best way to avoid deficiencies and stay healthy. I am sure that most of my ancestors had no clue about the science behind what they were doing but they just knew what worked. I consider myself lucky that a good chunk of this knowledge was passed on to me and apparently it still works: I haven’t been to a doctor in more than 30 years except for a painful episode with a kidney stone. And, no, I have
not taken additional vitamins or other supplements during those years.

So here is what kept us going for at least 4 generations:
Food staples:
– bread (white – though it wouldn’t be as refined or bleached as today’s flour).
– potatoes (peeled, washed, boiled, mashed)
– before potatoes where introduced in Europe their role would have been filled by dry beans, peas, lentils, etc.
– sometimes a meal would be based on rice but this was seen as a luxury

Vegetables (summer season):
– lettuce (can’t beat a cool salad on a hot day)
– spinach (early crop high in iron and vitamins – usually cooked but can be used as salad)
– purslane (high in omega3 fatty acids and vitamin E – usually cooked but can be used as salad)
– swiss chard (used mid summer when spinach tends to bolt – always cooked)
– endive (either cooked or as salad)
– radish (said to ‘cleanse your system’ – used in salads or sliced on bread)
– rhubarb (maintenance free perennial – cook stems and sweeten to use as vegetable or in jams) [use in moderation because rhubarb is high in oxalic acid, which is nasty stuff if you get too much of it]
– strawberries (used fresh or in jams)
– tomatoes (high in vitamin C – used fresh in salads or on bread; canned as base for soup, meat tenderizer)
– cucumbers (high in vitamin A,C, phosphorous, magnesium and other minerals)

Vegetables (rest of the year):
Most of these would be stored throughout at least part of the winter season and therefore be used as cooked vegetables, in stews, etc. They tend to be more filling then summer vegetables and would rarely be used raw in salads.
– cabbage species (good source of Vitamin C, amino acids)
white cabbage (is really just meant for sauerkraut production folks)
red cabbage (served with enough vinegar to change its color)
savoy cabbage (tastes much better than white cabbage)
– cauliflower
– kale (high in vitamin C and various minerals)
– brussels sprouts (high in vitamins A,C and folic acid)
– leeks
– onions
– rutabagas (high in calcium)
– broccoli (high in vitamins A,B,C and phosphorus and potassium)
– peas (moderate amounts of vitamins A,C, calcium, iron, phosphorus – used as vegetable or as soup)
– green beans (high in vitamin A,C, dietary fiber – used fresh or canned)
– carrots (excellent source of vitamin A and beta-carotene)
– red beets (good source of carbohydrates)

This is a very complete list and not all crops were grown each year or by each family but finding 10-15 crops in a garden in the course of the year was the rule rather than the exception. Most of these crops grow best in temperate climates, so if you live in a warm or hot climate: forget about summer and grow them in the winter.

To round out the picture: the farmers usually had some apple and pear trees and sometimes plum trees in their yard. Then there were red and black currants, raspberry, blackberry and alderberry bushes. Most had at least a few chickens to turn food scraps into eggs and were fattening 1 or 2 pigs per year for personal use. Not much beef was consumed because dairy cows were supposed to be milked (some of that milk was for personal use). And a 10 year old cow can give you some really tough meat. If goats and/or sheep were kept their milk was used for cheese making. Fish might be consumed once a week because it had to be purchased even though it was readily available. Some crops (potatoes, onions, peas, beans) would mostly be grown in the fields for marketing purposes, but part of the crop was kept for personal use.

Food storage.
I won’t bother to tell you about canning; many articles have been written about it already. Actually my preferred way to preserve vegetables is to freeze them because, if you do it right, frozen is hard to distinguish from freshly harvested. And, barring power outages, nothing spoils. With the exception of lettuce, radish and cucumber, all vegetables mentioned above can be frozen. Kale, leek, peas and beans can be frozen raw if needed, all others should be cooked first. Onions and rutabagas are usually stored dry, but if there are quality concerns or your onions won’t dry properly, there is no harm in processing/freezing them. Cabbages, brussels sprouts and cauliflower can be stored from 2 to 6 weeks depending on temperature and quality of the crop. If their outer leaves turn yellow you should process or eat them. Carrots and beets can be kept several months in a cool somewhat moist area. In cold (not frozen), damp soil they will keep till spring without much deterioration. Cabbages, brussels sprouts and kale can be kept in the garden as long as temperatures don’t drop much below freezing. To keep them from growing too large in the fall, you can lift them. This means you pull them straight up until you hear some roots break but leave the plant in the ground. This will keep your plants fresh but prevents additional growth. Leek will survive a light frost as well but its leaves become less appetizing once the plant stops growing.

Food preparation.
There’s plenty of recipes on the internet so I am sure you can find something you like. However preparing your food correctly is very important because if you do it the wrong way you will loose all your nutrients to the drain or the kitchen sink. Here are the important steps: – Cook your veggies with salt: about 1 teaspoon (meal) to 1 tablespoon (large batches for freezing) depending on the size of your pots and pans. The reason is that you want to prevent the cells from bursting open during the cooking process (think salt water fish in fresh water). Don’t worry about your salt intake because most of that salt will disappear down the drain again. I you get it right, it won’t even alter the taste of the food.
– Do not overcook your veggies. If you can stick a fork into the stems (beets, carrots, etc.) without much effort then they are done. Again you do not want the plant’s cells to spill their guts any more than you have to.
– When freezing your vegetables, you really only want to blanch them:
– Cook them a few minutes less then you would otherwise.
– Immediately pour the boiling water out of your pan and fill to the rim with cold water
– Immediately pour the hot water out of your pan and fill to the rim with cold water
– This water should stay cold or only get luke warm: pour it out
– Put the food in plastic bags or boxes and put it in the freezer
– When serving frozen foods you only need to heat them to the proper serving temperature; no need to cook them again. A microwave works great for this purpose.

I have read advice on gardening ranging from: ‘here’s a list, just get those seeds’ to ‘just eat what you like’. I agree with neither. Getting seeds if you don’t know how to grow them or refuse to eat them afterwards is a waste of your efforts. Just eating what you like increases the chances you will develop some kind of deficiency (unless you happen to like broccoli, kale and cabbage – or follow Victory garden which uses a very well rounded subset of the list above).

My advice is: variety, variety, variety. Your body knows exactly what it needs and, given the opportunity, will pick those things in the right quantities from the food you give it. It doesn’t get much easier than that! Your body is also capable of storing most minerals and vitamins in one form or another (sometimes as precursor molecules) for up to a few months. So there’s no need to worry about what you eat on any given day. Tastes are acquired. I heard from my parents that kids in the old days didn’t want to eat certain foods anymore than kids do today. However they weren’t given much of a choice. Their own parents knew from experience that without the (vitamins and minerals from) vegetables, sickness and mortality skyrocketed. In Europe this situation persisted until around 1950. If you are serious about prepping you should know by now that we can get back to such a situation in a hurry.

Part 2: Why I am switching to an indoor setup:
Last year I read a primer on aquaponics on and deep inside there was the conviction that I too had to pursue this angle. Having had the time to reflect on that conviction I believe it has something to do what is coming our way. As of today I can think of two primary reasons:
– Fukushima-type reactor melt-downs
– Climate change

I am sure most of you know what Fukushima stands for. After matching atmospheric particle dispersion maps generated in Europe to systematic denials of North-American governments, I had quickly seen enough and got hold of a geiger counter. Even this summer, if we get rain after a dry spell the unit shows elevated readings when put it up against my rain gauge. The levels are not worrisome at this point in time in so far as many people on this planet live in areas with higher radiation without suffering noticeable negative effects. Having said that, the pattern is repeatable so there must be something raining down on my food. I am afraid that Fukushima will turn out to be just a warning of future nuclear disasters. Given that in many aspects it was a fairly standard type plant (albeit in an unfortunate spot), we need to seriously consider the possibility that we will see a dozen or more Fukushimas in the northern hemisphere due to grid down and/or extensive coastal flooding scenarios. Unfortunately both of these have a probability of happening this decade that is too high for my taste. So its time to prepare for that eventuality. My personal attitude on this one is to prepare for the worst and hope for the best.

When I mention climate change, I am not referring to the mainstream media (MSM) angle which blames everything on man-made carbon dioxide emissions and so it wants to tax them. Which is very convenient for MSM’s owners who seem to be trying hard to get global weather patterns under control. Trying to control a complex system is a tough job because it doesn’t necessarily react the way you expect. It is also an expensive proposition, so if you can use your mishaps to get taxpayers to fund your research, that’s an added bonus. [One’s got to admire that business model.] Now I know that this sounds a lot like some conspiracy theory. I have no interest in promoting those, however the weight of historical evidence (check the adventures of the vikings in Canada, for example) suggests that MSM is blowing another smoke screen. Which leads me to follow the money instead.

An even bigger influence on earth’s climate is our solar system. On the one hand sunspot data suggests we should expect a cooling trend for the next 20 years. On the other hand satellite images from other planets suggest they are actually warming up. There is rampant speculation in some circles on the internet as to what would cause this but I haven’t seen anything conclusive that’s worth mentioning. Whatever may happen, physical evidence and the written records of our ancestors suggest that drastic climate change can come very quick. Think frozen mammoth with palm leaves between his teeth. I do not believe that I will join that mammoth otherwise I wouldn’t need to prep. All I am saying is that to blindly assume all things will continue to be the way they always have been during my (relatively) short life is dangerous at best.

While working on this article, had a link to an article by Kellene Bishop that asserts we may be entering a seven year famine. It points out several more reasons why you may want to get your garden out of sight and an aquaponic garden would fill that bill rather nicely; it can also be used by people who have no access to a land area.

Of course, it doesn’t help is that my outdoor vegetable garden isn’t doing all that great this year. The weather events we have had since the start of the growing season aren’t too extreme in and of themselves. Its just that the continued sequence of alternating high rainfall, high heat, baking sunshine and high winds is starting to stress the plants. They look like the big rains we have had are stunting their root systems and so the plants are unable to properly cope with the other events.

Alas, if our climate is really shifting gears, this situation will be the norm for coming years. And so its prudent for me to shift gears as well and I have started by building a small test setup this year with just 4 grow beds to try a bit of everything and whatever it yields is fine with me. Because it is a setup so very different from traditional soil based gardening, I have done some comparative tests on germination, fertilizing and growth medium particle size. So far I am quite pleased with the results and plan to go with 16 grow beds next summer. That should allow me to grow everything except my corn under a roof. I will relate some of my observations later but will first discuss my setup.

My choice of setup:
There are a variety of ponics systems and about the only thing they have in common is that they don’t use soil. The so-called hydroponics system only uses water and no growth medium. It is mostly used in commercial operations. I wouldn’t recommend it as a home based system because you will have to content with algae and fungal problems. Apparently algae will quite happily interfere with a plant’s root system and need to be controlled at all cost. It also has a higher startup cost than other types of ponics systems due to required electronic control systems.

A complete aquaponics system is the most elegant because the plants live from the waste that the fish create, while in due time you can harvest both fish and vegetables. You can even grow your own fish food in the form of duckweed, making for an almost closed system that just needs sunlight and some minerals. I do not have a real aquaponics setup because the fish are missing. The reasons I chose not to use fish are of a practical nature. My growing season is too short (200 days at best) and temperatures vary too much day to day for the fish to really thrive. I have had a few aquariums over the years which worked fine but those were electronically controlled environments which I cannot hope to replicate with a solar powered aquaponics system at my current location.

In an aquaponics system you do need a growth medium to act as a biological filter that turns the fish waste into nitrates for the plants. I chose to keep the growth medium because it is a more natural environment for plant roots since they can grow in the dark, meaning no algae problems around the plant roots. It also means that I can run the system on manure tea if other forms of fertilizer are not available since the growth medium will act as a biological filter as well. Thirdly, nature abhors a vacuum and if you do not put your plants in an environment with lots of good microbes, the bad ones WILL move in. Again a growth medium is ideal to get the proper environment.

How I created a grow bed:
I started by cutting a plastic 55 gallon drum in half lengthwise to give me two grow beds. Clean them out really good and leave them outside in the sun for a few days so UV radiation can break down any leftover chemicals. If at all possible use drums that were used for food ingredients or chemicals that are approved for use in food factories. The grow beds lay side by side on a pair of 2×6’s, supported by a small piece of 2×4 on each side so they don’t slide around. You can find good pictures of how to build the supports in this document, which is where I got my first ideas. You will also see that my setup uses far fewer parts than the one in the document though. In the lowest part of each grow bed’s bottom I cut a 1″ hole using a hole saw. From the outside I put 1 leg of a 1″ poly tee through the hole. This leg has a male pipe thread on it. Inside the grow bed I screwed a 1″ female adapter onto this MPT leg. Make sure to put a liberal amount of silicone caulking around the MPT leg so your grow bed won’t leak. You may want to test this before you put the growth medium in your beds.

Then I put a 8″ piece of 1″ poly pipe on the female adapter. This allows the end of the pipe to reach above the growth medium in the bed. Which means that you can always reach the bed’s drain hole in case it gets plugged (one of my cucumbers decided to put a root through it …). On the side of the hose/female adapter, about 2″ above the bottom of the grow bed, I drilled a 1/4″ drain hole. This hole determines the speed at which the water drains out of your grow bed. Putting it a few inches off the bottom leaves the plants a small emergency water supply should there be a pump problem. Over top of this drain assembly I put a piece of perforated plastic drain pipe to keep the growth medium from blocking the drain hole. This drain pipe is 4″ diameter and can be cut lengthwise so it lays flat on the bottom of the grow bed. A length of 1 feet will do just fine. The drainpipe is shown in figure 25 in the above mentioned pdf document.

On top and around the drain pipe I put small rocks to act as fillers so I don’t need as much growth medium. In a true aquaponics system you will want as much growth medium as possible because you need a large biofilter to buffer against quick changes in water quality. However plants can handle a wider variety of circumstances so I can get by with a lot less growth medium. My beds are filled with about 6″ of medium at the center of the bed and spread out horizontally. This will fill the drum halves until the point where their walls are vertical. That gives me maximum growth space for minimum growth medium.

Growth medium:
Aquaponics people mostly seem to use expanded clay or pea sized gravel. I read about one setup in South America that used white sand. I couldn’t find expanded clay at my local garden center but did try pea sized gravel along with much finer gravel that I got from a brook on our property. Based on my test results I have to say that the plants definitely prefer the finer gravel from the brook. Germination is better and initial growth is faster; as the plants mature the differences tend to get smaller. Presumably because finer material has a much larger surface area per cubic inch, creating a more even moisture/air environment for plant roots. As a result I am going to fill my beds with gravel from our brook. Since its consistency is close to that of coarse sand, you could use that instead of pea size gravel. If you decide to use sand you may need to put a layer of pea sized gravel over the drainpipe to prevent the sand from dropping into it. Do not be tempted to go cheap and use garden soil. It contains way too much silt and possibly clay. Both particles are microscopic in size and under an ebb and flow situation they will collect in low flow rate areas and form a layer that won’t be appreciated by you or your plants.

How to create a system:
Creating a functioning system from the grow beds you made (doesn’t matter how many) is fairly straight forward. Remember that every bed is outfitted with a tee. I use the two legs that are open on the outside of the bed to connect the beds together with 1″ poly pipe (potable water rating), no hose clamps needed. One piece of poly pipe has a tee in it which is located above an opening in the collection tank. And that is the entire system for collecting the water that I pump into the beds and returning it to the collection tank.
The collection tank itself is simply a 55 gallon drum laying on its side (you want to keep the distance the pump has to lift the water as short as possible) with a few access holes for hoses and to add manure tea/fertilizer, made at its highest point. My collection tank is white which means I have some algae growth in it that I need to clean every once in a while. If you can: get a black drum or paint it black or put it in a hole in the ground to avoid sunlight from entering the tank. This greatly reduces algae growth in the tank.

To pump water into the grow beds I use a 1,000 GPH bilge pump (located at the bottom of the collection tank) with a 1″ outlet that is connected to a poly pipe (with hose clamps) that runs to the top of the grow beds. [Because the return lines are gravity fed the bottom of the grow beds are located above the top of the collection tank.] At the top of the beds the poly pipe connects to a 1″ PVC pipe. This PVC pipe runs across all 4 beds. In the middle of each bed there is a tee in the PVC pipe and connected to that tee is a PVC ball valve with a 1/2″ opening. I found that I have to be able to adjust the amount of water going into each bed individually because of the variety of crops (and the different growth stages they are in) in the system at a given point in time. I have outfitted each valve with a splash guard (made from a 1 quart plastic bag) because plants do not like to be wet 24/7.

The waterpump operates on 12V so I can run it directly off a 12V battery that is charged by a solar panel. Operation has turned out to be very simple. I start a cycle by running the pump for 20 seconds. Then it is off for 30 minutes; this drains the grow beds to the point where water is just dripping into the collection tank. At that point you should start the next cycle. The actual length of the cycle will vary with the way you construct your grow beds. I have seen reports from people with larger beds that had a 2 hour cycle. You may be able to find an electronic timer that allows you to fine tune your cycle.

What I have described so far is your basic system. You can now let your imagination run wild to improve on it. For instance I built my own timer using a microcontroller that controls the bilge pump through an automotive type 40A relay. But the microcontroller had unused pins. That is an eyesore for any DIYer. So the system has been expanded with a voltage sensor, temperature sensors and float switches. This allows the microcontroller to actively manage water temperature via a second water pump and an external heat exchanger. It can monitor battery charge levels and stretch the flooding cycle if voltage drops too much. That will slow down the plants but at least it keeps them alive. It also monitors water levels and pump action to prevent pump damage. If it finds an issue that needs my attention it will signal this by turning on a red LED instead of a green one.

As I mentioned way back when, one of my goals is to grow my veggies under a roof. I haven’t build the housing yet but its on the drawing board and I have pretty much settled on the design. It will be a cross between a cold frame and a greenhouse. 2 units of 8′ x 8′ x 4′ each. An 8′ x 8′ footprint holds 8 grow beds with a walkway in between. Each 4′ high side panel will have a 2′ translucent clear pvc panel at the top and white siding below. A unit’s roof will be made of 2 4’x8′ translucent clear pvc panels that can be easily removed. Putting the grow beds on the floor will leave the plants with about 3′ of headroom which is enough for 2 tiers. For instance tomatoes, cucumbers and pole beans can be easily made to grow to a second story made from a horizontal sheet of lattice with lettuce, spinach, etc growing below. Similarly peas love to climb a wall of chicken wire. If I start the system early I should be able to get 2 crops or multiple harvests out of most beds, improving production considerably.

First impressions on germination:
This is what really blew me away. You basically throw your seeds on the rocks, barely cover them and walk away … just to see the plants pop up in record time. Due to our short frost free season there are a number of crops that need to be started indoors. This year I divided those seeds in two portions and put half of them in trays with potting soil (mini greenhouses) to start them in the living room as I have done for many years. At the same time the other seeds were put in an aquaponic grow bed whose temperature ranged from high 40s in the morning to about 55 degrees at the end of the day. All crops emerged 1 to 2 days quicker in the grow bed than in the mini greenhouses and then simply kept outgrowing them.

Two striking examples:
– I planted 18 red cabbage seeds, 9 in each medium. In the aquaponics grow bed all 9 emerged and grew into healthy plants; in the mini greenhouse 1 cabbage plant emerged which died after 2 days.
– I had done a germination test of my tomato seeds in the living room to see how viable they were. I just kept them there until I saw a root come out of the seeds. No longer needing them I threw them on one of the aquaponics beds without bothering to cover them. Two days later I found a bunch of 1″ high healthy tomato plants some of which are now setting fruit.

On fertilization:
I started the system out with using just manure tea. Apparently you can make tea from pretty much any type of manure as well as from compost. Your mileage will vary because each type of tea will have different amounts of NPK (Nitrogen-Phosphorus-Potassium) in it, chicken manure being the highest rated.

Using just manure tea, the plants grew okay but not as I expected. They looked pale green and spindly as in suffering from nitrogen deficiency. After letting them muddle on for about a month, I decided to add some commercial fertilizer (10-10-10) that I use in my outdoor garden. Took a 2 handfuls of it, put it in a bottle with two quarts of water, shook for a minute and dumped it in the aquaponic system’s collection tank which held about 40 gallons of water. [Repeat once a week when plants are small and increase frequency as required during the season.]

Once again the system did not let me down. The plants turned noticeably darker pretty much overnight and took off. Growth rates easily match the best performances I have seen in any outdoor garden. Because the commercial fertilizer only supplies NPK I still feed the system a pail of manure tea once or twice a week along with a few tablespoons of sea salt once a week to make sure there are enough trace minerals in the system. Kelp is supposed to work really well too but for me it is expensive to get and as long as I see no deficiencies in the plants I see no need to use it.

On water issues:
The water I use comes from a 150 ft deep well we use for drinking water so I am not worried about its quality or contents. Water usage is minimal when the plants are small. Now that all beds are filled with more or less fully grown plants setting fruit and seeds, they use up to 8 gallons per day. Tomatoes and cucumbers seem to be the biggest users. Unless your water is very hard, you may need to add some lime or other pH booster to your system because the water will get more acidic as the season goes on. This is due to bacterial activity in the grow beds. My setup has come down from around pH=6.8 to pH=6 which is about the minimum I want to see. With the exception of red beets the plants don’t seem to mind at all though. I did buy nitrate and pH test kits so I could see what goes on in the system. I never see any measurable free nitrates so I guess I could put more fertilizer in the system but the plants look healthy so I won’t over do it.

On bugs/diseases:
I haven’t noticed any real problems yet. As expected there have been some caterpillars showing up on the cabbages. I tried to get rid of them with diatomaceous earth. It killed some but not all. Since I am a bit pressed for time this summer I sprayed the cabbages with a systemic chemical (same as you use for corn borer) which takes care of the problem in a day or two. An easy way to avoid them is to put screening over the beds where you grow these crops as it keeps out the butterflies. But make sure not to keep the bees away from your tomatoes, cucumbers, beans and peas. I didn’t expect to see any soil borne diseases in the beds and to-date they haven’t shown up. Nor have I seen any other signs of trouble.

If there are readers that are venting steam from their ears by now because I have broken all the rules of aquaponics and organic gardening: that’s okay, I understand. But I am rather pragmatic about it. My goal is to grow food; lots of it in a small space, with minimal inputs. I need to know what I can and cannot do. I won’t put stuff that I know is bad for me on my food, but if it is not bad and fixes a problem for me, I have no problem putting it on. Do I think fertilizer and chemicals will always be readily available? No, that is why I am trying to find the best alternatives while I have the opportunity.

Well, I think I have covered just about all aspects by now. I hope this will give you enough information to determine if (modified) aquaponics is something that fits your preparation needs. My garden is fairly large as I grow veggies for a few families. The goal with 16 grow beds is to match that output. Your system could be much smaller. For instance I still have 4 unused (20″x4″x4″) planters laying around. I plan on sealing their drainage holes and turning them into a small indoor system to grow herbs and start seedlings indoors. Together with a 5 gallon pail, an old aquarium pump and a timer they should do the trick. Happy gardening.

JWR Adds: I only recommend hydroponic gardening for families that have very copious and continuous power such as that provided by micro-hydro, photovoltaics, or an on-site natural gas well with redundant generators. Without a stable power supply, electric pumps don’t pump, and you’ll be back to traditional dirt gardening, very quickly.