11/3/11

Planning for 2012 Outdoor Season

The 2011 outdoor season is complete! I’m happy to say that it went much smoother than 2010, when I had a few mechanical and design errors that significantly handicapped the growing. As a result, I learned a lot more this year about the plants. Of course, I also discovered that my new design still needs some improvements.
 
My half-barrel system provided adequate depth for the plants to establish deep roots, insulated from the summer heat, and my very conservative growbed to tank volume ratio of 1:2 provided ample nutrients to the roots.
 
With only one pump and three barrel-halves, I connected all the barrels via PVC pipe with one siphon at the opposite end from which the water entered the barrels. Unfortunately, the piping connecting the barrels was 1 to 1.5 inches above the bottom of the barrel half. This meant that only the barrel with the siphon could drain completely – the others would have standing water below the connecting pipes.
 
Once the cucumber and squash roots reached the standing water, they plants began to weaken. This culminated in root rot that brought the once thriving plants to an early demise.
 
Additionally, I found that my mechanical timers did not keep reliable time. I had set the pump flow for 15 minutes, which would provide enough water to just start the siphon. Unfortunately, I frequently found that the timer cut short, so the siphon didn’t start, leaving the roots soaking for far too long. To circumvent this, I kept the pump running continuously. With no time for the roots and shale to dry out between cycles, it probably exacerbated the root rot problem.
 
To avoid these problems next year, I plan to do the following:
  • Put a drain in the bottom of each barrel
  • Connect the drains to a single siphon outside the barrels
  • Pump water in through the bottom of the siphon system. If the timer cuts short, water can drain back to the tank through the pump
 
Planned System Design Outdoor Season 2012

 
Planned Siphon System Design for Outdoor Season 2012

I will also swap out the fish pond for an IBC tote to take up less space. Additionally, I may move the location of the aquaponics, as it only gets full sun between 9am and 3pm.

 

8/24/11

Squash and Cukes!

By August, I had some great looking squash and cucumbers growing.

Cucumbers (left) and Squash (right) on 8/16/2011
The squash grew very vigorously and produced lots of buds this summer. Unfortunately, the three squash plants kept producing all same sex flowers at one time. As a result, there weren't many flowers of the opposite sex to pollinate them. I got all my squah from the brief periods when the two sexes overlapped (at the end of one cycle and beginning of another). Next year I'll stagger the squash planting to increase the likelihood of both sexes of flowers existing at the same time.

8/2/11

Outdoor Season Update

This summer's growing has been progressing steadily. I've harvested the basil a few times, and the cucumbers and squash now have fruit beginning. The cukes and squash have had flowers for at least three weeks, but until recently all the flowers were male - that means no fruit. I thought the lettuce might grow well under the shade of other plants, but so far they've just stayed small and dormant. Bell peppers have produced a few fruits but few new flowers. Nitrate levels in the water have remained very high (~80ppm) and I've put some Maxicrop plus Iron in as well. I started up the tank with pure ammonia, so I think there was a lack of some trace nutrients, including iron..

Grow beds on 7-26-2011
Squash (foreground), Lettuce, & Jalapeños (background)
Cucumbers (foreground), Peppers (mid), & Lettuce (background)
Basil (R) with Small Hot Peppers (L)

7/9/11

Tengo Muchos Jalapeños (y Otras Verduras)!

In the month since I took my tomato plants out of the grow bed inside, the jalapeños' growth exploded. They've grown tall and have a profusion of flowers. As I've mentioned before, the I was surprised that the jalapeños flowered, due to the predominately blue light of the metal halide bulb. Such light is best for vegetative growth.

Last week I harvested the first fruit: they are about 3 inches long and very spicy! They made for a piquant corn chowder. I have 16 more that will be ready to harvest soon and at least another 15 buds and flowers.

3" Jalapeños on 7/05/2011
Jalapeños Ready for the Chowder

Meanwhile, the chard has re-grown tremendously...

6/7/11

First Custom Contracted Aquaponic System Built!

I'm pleased to report that I have just completed construction of my first custom aquaponic system for a client based in Little Compton, RI. See more pictures and find out the details by visiting the new Custom Client System page!

First custom built aquaponic system: 4' x 2' x 1' grow bed with 3' x 2' x 1.5' fish tank using an autosiphon

    6/5/11

    Growth Spurt!

    The tomatoes, chard, and peppers in the basement system are now growing vigorously! The tomatoes especially have surged in height. As you can see below, in just four days each tomato plant gained about five to seven inches!

    Left: Grow bed on 5/27/2011 Right: Grow bed four days later on 5/31/2011
    I needed to transplant these tomatoes, because I was heading out on vacation, and I worried that they would grow into the light, causing a fire hazard. Originally, I planned to transplant these into my outdoor aquaponic system; however, they had grown so fast that the outdoor system didn't yet have the necessary nitrate levels. Instead, I transplanted them into pots with soil. To make up for these, just before I left, I planted more tomato seeds, in addition to cucumbers and summer squash. By the time I return, I expect they will have sprouted and the outdoor system will have enough nitrate to receive them.  I'm interested to compare the growth and output of the tomatoes that spend their whole life in the aquaponic system, the ones I transplanted to soil, and others that I've had in soil since seedling stage.

    I was happy to discover through this indoor tomato experiment that tomatoes could thrive in shallow grow beds. The expanded clay grow bed is only about three or four inches deep, yet the plants grew tremendously. You can see from the photos below that once I washed the clay pebbles out of the roots, they were only a few inches long. Of course this is a direct result of the aquaponic growing method: with nutrient rich water delivered regularly right to the plant, roots do not need to travel far to find sustenance.

    Roots of heirloom tomato before transplant 6/1/2011
    I reason that the shallow bed worked well because of the cool temperatures in the basement. Outside, such shallow beds would fail because the tomato's shallow roots would get baked in the sun. If I used this for future indoor projects, it means I could reduce the amount of media I need to purchase and the amount of weight the table must support.

    Meanwhile, the chard has grown rapidly and the hot peppers have sprouted flowers (much to my surprise because of the dominance of blue light from the metal halide bulb).

    Two types of rainbow chard in clay grow bed on 5/31/2011
    Buds on hot pepper plants 5/31/2011

    5/19/11

    Meanwhile, in the Basement....

    While the outdoor system is cycling, I’m continuing to grow indoors. I have a few rainbow chard plants that are now growing tremendously. I’ve also started some sweet peppers and heirloom tomato seedlings that I plan to transplant into the outdoor system. So far the tomatoes are growing very well, at about five inches tall. At over a year old, the pepper seeds delayed germination; however, they finally sprouted and now stand at half an inch tall. The system has many fewer plants than it can support currently: nitrate is about 30ppm at least. I plan to put this nitrate rich water into the outdoor system to kick start it for the transplants.

    
    Rainbow Chard 5/17/2011

    Rainbow Chard with Tomato and Pepper Seedlings 5/17/2011
    

    Outdoor System Launch 2011!

    In the first week of May I completed the initial setup of my outdoor flood and drain aquaponics operation. I grew outside for the first time last year, and I’ve made substantial alterations to the system design based on my experience (click for diagram of old system). This year, I’ve replaced my old shallow, clear plastic grow beds with 55 gallon blue plastic barrels cut in half lengthwise. I’ve also replaced the ¾ inch gravel with ¾ inch expanded shale (from Rob Torcellini of Bigelow Brook Farm). Lastly, I’ve installed an autosiphon to flood and drain the grow beds, based upon the design from Affnan.
    Grow bed with expanded shale and autosiphon viewed from above (left) and below (right)
    Grow bed with wood frame and cement block stand
    The updates to the system should prove fruitful. The grow beds are now a 12” deep in the middle, about three to four times deeper than last year. This will allow for much longer roots, more surface area to absorb nutrients and water, better insulation from the heat, and greatly increased area for nitrifying bacteria growth. I’ve switched to expanded shale for its light weight, moderate price, and pH neutrality. The autosiphon provides me with a failsafe method to flood and drain the grow bed – no moving parts and no possibility to overflow.
    Still using the 160 gallon plastic fish pond, I’ve set up three barrel halves for a roughly 1:1 ratio of tank to grow bed volume. The barrels are all connected with 2” PVC pipe and use one autosiphon at the opposite end at which the water will enter from the pump. Hopefully one siphon will be sufficient for the system.
    Given the short growing season in New England, plus the time delay needed to cycle the system to build up nitrifying bacteria, I’ve decided to try a fishless cycle. Without fish, I can put pure ammonia into the system and achieve much higher levels of ammonia than the fish could tolerate. With ample ammonia, I hope that the nitrifying bacteria will establish and multiply relatively fast. Unfortunately, the one key ingredient the bacteria need – heat – is seriously lacking this month. The bacteria flourish in 75-85oF temperatures, and May has delivered cold, wet weather.
    Meanwhile the fish are happy inside feeding some chard and tomato and pepper seedlings! See next post for more on that. Also, there are three more barrel halves that I plan to turn into additional grow beds soon.

    5/1/11

    Winter Growing Season

    The winter growing season was a smash! The lettuce did quite well, and I harvested about eight salads that fed four to six people each from February through April, about two-and-a-half salads per month! The first six of those salads came from the clay pebble bed that had densely planted seeds. The dense planting stimulated quick, vertical growth. It also ensured that plants did not grow woody stems, keeping the growing tip low, just above the surface. I harvested this like mowing a lawn,, cutting at about 2” high straight across. The plants responded well! For the first two months I harvested at a staggered pace, which kept the demand for nutrients relatively constant because some plants were in the high demand regrowth stage as others grew slowly near full size.

    Mixed lettuce in clay pebble bed on 2/18/2011 (top) and 3/26/2011 (bottom). 
    Gray coloration on bottom is due to grow light being off. Note that the gravel 
    grow bed seen in upper right of both pictures has significantly smaller plants.
    Meanwhile, the gravel grow bed which had plants spaced about 6” apart, as recommended on the seed packet, grew very slowly, so I did not harvest until late March. The plants did bush out nicely, each producing far more lettuce per plant than the dense plantings of the clay bed. The bushy lettuce led to woody stems and larger leaves, which I found could only get a few harvests per plant before the leaves got too tough or bitter (lots of white sap in them). 

    
    Gravel grow bed on 4/28/2011 before the last harvest.
    
    Conclusion: unless I need pretty heads of lettuce, I should plant the seeds dense and harvest often.

    And what about the other plants in the system? Well, the chard...

    4/30/11

    Water Wheel Conclusion

    In February, I began testing a prototype of a water wheel biological filter (see original post describing wheel here). After about a month and a half of testing, I found that it provided decent biological filtration but that it had mechanical flaws. I’ve since decided to retire the project, at least for the summer season. Here’s the scoop:

    My neighbor and I built the wheel from ¼” thick, untreated plywood. While pressure treated or stained wood would have resisted rot and water absorption, I did not want to risk chemicals leaching into the water. We also experimented with some Plexiglas, which proved too difficult to cut as it fractured easily.

    The wheel was connected to two screen-covered drums by PVC pipe, the pipe was supported by a wooden dowel, and the dowel was suspended by strings at each end. As you can see in the video on the original post the wheel turned well initially; however, after a few days, the wheel noticeable slowed down, eventually coming to a stop. I found that the dowel bowed due to the weight, creating extra friction, so I replaced the dowel with a metal pipe. Nevertheless, after a while the wheel slowed to a stop, too. The wood had absorbed water which weighed it down and it’s possible that bacteria growth also added to the weight. Interestingly the wood did not warp noticeably, but after the trial period, it was covered in little black dots of mold – probably not good for water or our air quality. 

    Black mold growing on water wheel paddles (left) and screen drum (right)
    Meanwhile, I was designing my flood and drain and deep flow technique (DFT) systems* for the outdoor season this summer. The DFT would use the water wheel as its biofilter*. During my research, I learned...

    2/11/11

    Winter Growing

    After some experimenting with grow bed media in the early winter, I planted my indoor crop of lettuce and rainbow chard in mid-January. After about four weeks the plants look quite healthy. All seeds germinated in the expanded clay bed, and I then transplanted a few into the gravel bed. I've given the lettuce in the gravel bed plenty of space, and I'm curious to see how differently the plants grow in the dense and spaced scenarios.
       
    Expanded clay bed 2/3/2011
       
    Expanded clay bed 2/9/2011
    
    Gravel bed 2/9/11
    The conditions in the water are not ideal right now: while there is plenty of nitrate (plant food), the pH is about 8 and the temperature is about 62-65 oF.

    A pH of 7 or just below is ideal in aquapaonics. Plants absorb the most nutrients in slightly acidic conditions (pH < 7)  while fish prefer it slightly basic(pH > 7). So we compromise and try to make the water pH neutral (pH 7). The nitrificaiton process (turning fish waste into plant food) naturally lowers the pH, so the fact that mine is above 7 means other factors are at work. First, my gravel has lots of limestone in it, and the calcium it contains leaches into the water and raises the pH. Surprisingly, the clay pebbles also raise the pH, even though they are billed as pH neutral. I tested them by letting some clay pebbles sit in fresh tap water (pH 7) for a week, and they raised the pH up to 8 or 9. The plants are growing well now, but I'm going to experiment with adding some lemon juice to lower the pH over the next week.

    As for the temperature, the nitrifying bacteria prefer water between 72-75 oF. At lower temperatures, their growth rate slows down significantly.  I could use water heaters, but they are very energy inefficient, so I'm trying my hand under cooler temps. The goldfish and lettuce, however, love the cold water. Currently, there is plenty of nitrate in the tanks, and I will monitor the tank to see if the bacteria are able to maintain sufficient levels as the plants near harvest stage.

    2/1/11

    Water Wheel Prototype

    19th century water power is alive and kicking!....er, spinning! My water powered biowheel* prototype is complete. Pumped water powers this overshot-style wheel (I'm not quite ready for the Pelton wheel yet), which turns two attached drums. The drums are wrapped with multiple layers of fiberglass screen to provide surface area for nitrifying bacteria to colonize. As the wheel rotates, the bacteria will get a consistent does of moisture and oxygen, which will hopefully lead to vigourous growth and biological filtration (converting fish waste to plant food). You can see a video of the wheel in action below.


    Now my wheel will go into test mode: I will fill the tank with fresh water and see if the wheel can provide enough biological filtration to effectively start up or cycle the tank.**

    Friction was literally the biggest obstacle to getting the wheel moving. Specifically the wheel had to be able to overcome the resistance the tank water would put against the paddles. To combat this, I angled the paddles so they retain more water as they spin down and then release water as they start to spin upwards. Additionally, I just barely

    1/2/11

    Aquaponics in New England: Introduction

    Can aquaponics work as an economically competitive system in New England? I admit that the technique may not initially appear suited to the region: traditional farming and fishing have had long, successful histories in New England, and one of aquaponics' main advantages, water conservation, would seem best applied to an arid climate. However, I believe that aquaponics fits quite well, and here's why:
    1. It can supplement the offerings of traditional farming and fishing where they have limits;
    2. It can significantly improve the sustainability of produce and fish production; and
    3. It can foster a substantial increase in local food production that will strengthen food security and protect our natural resources – especially important in a future with a changing climate and growing population
    Each of these three arguments is laid out in the individual posts below (Parts I-III), and you can download the a PDF of the complete paper here. My home state of Massachusetts will serve as the example throughout, and I use the term ‘traditional farming’ to refer to soil based agriculture including organic and non-organic. 

    As a life-long New Englander, I see aquaponics as a means to participate in the revival of its once thriving agricultural community, all while preserving its natural resources to the highest degree. I look forward to hearing your thoughts. Enjoy!

    Part I - Aquaponics in New England

    Part I of Aquaponics in New England discusses how aquaponics can supplement the offerings of traditional farming and fishing where they have limits. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes.

    Supplement Traditional Farming & Fishing
     
    First, it is important to understand the current state of agricultural affairs in Massachusetts. After a precipitous decline in the 1960s, the number of farms in the state is now on the rise (see Figure 1). As of 2008, the state had more than 7,700 farms (including aquaculture and nurseries).1 Many of these farms have hit on effective and profitable strategies, such as Community Supported Agriculture, farmers markets, and/or organic certification. The growth is fueled significantly by organic agriculture. Between 1997 and 2008, the number of farms in Massachusetts increased 28% while the number of organic farms increased over 3,000% (from 3 to 103).1


    Traditional Farming
    Despite the growth, traditional farming has limits in Massachusetts. Whether organic or not, traditional farms have a limited growing season. Many cold hardy species...

    Part II - Aquaponics in New England


    Part II of Aquaponics in New England discusses how aquaponics can improve the sustainability of produce and fish production. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes. 

    Improve Sustainability of Local Harvest

    Water Use
    In addition to providing a sustainable source of fish, aquaponics has other sustainability advantages over traditional farming, hydroponics, and aquaculture. First, these techniques use a lot of water. Traditional aquaculture methods use between 0.57 and 33 cubic meters (m3) of water produce 1 kilogram (kg) of fish, depending on method8 (See Table 2). Research at the University of Virgin Islands has shown that their aquaponics system uses less than half of the water of the most productive aquaculture systems: 0.25 m3/kg.8 On average, aquaponic systems use between 90 and 99% less water than traditional aquaculture systems.9

     

    Aquaponics also uses less water than hydroponic crop production. Aquaponic systems...

    Part III - Aquaponics in New England

    Part III of Aquaponics in New England discusses how aquaponics can fuel a significant increase in the region's food production. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes. 

    Help Scale Up Local Food Production

    Scaling up refers to significantly increasing food production to a level well above the status quo, dramatically altering the ratio of imported to in-state/region produced food
     
    Why Scale Up?
    Aquaponics offers the potential to scale up local food production for Massachusetts and New England. But first, why is scaling up production important to the region? As discussed previously, locally produced food tends to produce less GHGs. It also provides an opportunity for local employment, helps to reinvest money in the state or local community, and preserves open space and rural character of the region, supporting tourism and real estate values. Local food often tastes better, too, because varieties are cultivated for their flavors. In contrast, most commercial varieties are cultivated for their ability to withstand the assault of freezing, packing, and shipping hundreds or thousands of miles.

    In addition to growing demand for local food, climate change presents a major economic argument for increasing local food production. Most of the extremely high risk areas for water stress in the Tetra Tech study are in America’s major agricultural areas: the Great Plains and Southwest, including California.13 Globally, climate change will have an overall detrimental effect on agriculture, too.10 This means prices for imported food will...