June Aquaponic Update

It has been over ten weeks since ANY blog update, and more than that since an update on my aquaponic system.  I have made a lot of progress.   

After several frustrating months trying to get the system to cycle (establish nitrifying bacteria to convert fish waste into nitrites and nitrates) I sought help from the internet (specifically The Aquaponic Gardening Community).  I was to the point where fish waste was building up, raising ammonia levels in the water causing the fish to start dying.  And my plants were not growing at all.

Fortunately the main fix was easy.  My water pH was too low, the nitrifying bacteria could not live, and hence no cycling.  When I fixed the pH, it was pretty amazing how fast the cycling progressed, really over a period of only 3 - 4 weeks.  Once the system began to produce nitrates, the plant growth exploded. 

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Kaffir Lime

The above photo shows a small kaffir lime plant.  The leaves in the background were on the plant when I put it in the grow bed.  Before the system chemistry was corrected, they were turning white and falling off.  I thought the plant was going to die.  The healthy left foreground leaves have all appeared in the last six weeks. 

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Lettuce

Lettuce was one of the first things I planted in the system, probably in February.  The plants did nothing, barely staying alive, until the system cycled.  Now they are thriving.  It is really too warm for lettuce and it is a little bitter, but it is great to see it growing so fast and know that in the fall and winter I will be able to produce great salad greens.   

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Thai Basil

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Italian Basil

I have planted Thai and Italian basil, and both are growing quickly.  These are the first plants I am really harvesting and using.  The basil is delicious, and it is so great to be able to cut it, chop it, and have caprese salad with fresh basil and none of the waste that comes from buying bunches of basil at the farm market or grocery store.   

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Tomato

My tomato foliage is thiving, and the plants are starting to set fruit, though I have had far more flowers so far than I have baby tomatoes.  I understand that it takes a while to create enough nutrients in an aquaponic system to support fruit growth (as opposed to just foliage like basil or lettuce).  I also think I was overly ambitious with the number of tomato plants I planted.  I need to thin them out in the hopes that those remaining will have enough nutrients to set and produce fruit, but it is a hard decision to pull out plants (even though I would try to move them to outdoor containers).  

This post has focused on the plants, but my tilapia are also much healthier since I sorted out the system chemistry.  They are growing, and I think have doubled in size (at least) since I introduced them to the system a couple of months ago.  I did have about a dozen die before I got the system working correctly, but I still have 25-30.   

I have a few further corrections to make, and I continue to experiment with plants.  I ordered chelated iron which I am hoping will help a few plants that are turning yellow or still not thriving (parsley, cilantro, curry leaf).   I added two lemon grass plants today, and I think they will do well.  Actually hoping they don't do too well - I have a suspicion I will be dividing them frequently.  I have other herbs that are well established, including some tarragon and Mexican oregano. Overall while the system has a ways to go, I am at least seeing its potential, and the fantastic pace at which plants grow in an aquaponic system. 

Building our Aquaponic System - Part 1

The last unrenovated area of our home is a small greenhouse the prior owner of the house had installed in the narrow space between us and our neighbor.  We have never used the greenhouse effectively, and it has mostly been storage for bikes and garden supplies.  After finishing our basement renovation earlier this year, it was time to get the greenhouse in shape.

The Greenhouse Has Never Been This Clean

We think the greenhouse was built in the late 1980s.  It is well constructed with an automatically venting roof, gas heat (which needs repair) and plenty of electric outlets.  Its big problem is light.  Located in a north/south aligned alley between two town homes, it only receives a few hours of sunlight each day.

I decided the obvious solution was artificial light.  In researching lighting solutions, I soon discovered a much wider variety of options for indoor growing than simply adding light.  

After a lot of reading, I decided that a recent innovation in gardening called Aquaponics would be practical, interesting and educational for our kids.  

Before we could start adding the aquaponic system, the greenhouse needed repairs after 18+ years of neglect.  Jim Wheeler of Greenspace Gardens did a great job fixing broken glass, getting the ventilation working and replacing the faded plexiglass in the doors with nice tempered glass.  Janco, who provided the original greenhouse was far less helpful, but fortunately Jim was able to keep after them until they provided the required parts for the repairs.

Our New Grow Beds

The term Aquaponics is a contraction of Hydroponics, or growing plants in water and Aquaculture, or raising fish.   An aquaponic system grows plants largely in water that is circulated from a tank of fish, using the fish excrement to fertilize the plants, and the plants to cleanse the water before returning it to the fish tank.  Thus the system can simultaneously raise edible plants and fish.  Of course if you prefer it can also raise flowering plants and ornamental koi, but that is not our intent.  

When I first read abut aquaponics, I recognized the biological process as essentially the nitrogen cycle my daughter learned in school last year, where the ammonia excreted by the fish is converted by bacteria to a form usable by the plants as food.  I think there will be a lot more science education arising from this project.  

We will have three 2' x 3' growing beds, pictured here and a 180 gallon fish tank which is not yet installed.  I think the fish tank will be able to produce about 40 lbs of tilapia each year.  

Plumbing Fixtures for the Aquaponic System

The supplier for our aquaponic system is The Aquaponic Source in Colorado.  Sylvia Bernstein and her team at The Aquaponic Source have been extremely helpful and patient answering all of my questions. I timed the order of the system so that I could do most of the assembly over the Thanksgiving Holiday.  

I am glad I planned an extended block of time for assembly, but I have made a lot of progress.  The most complex aspect of assembly is the plumbing.  Water has to get from the fish tank to the grow beds, back from the grow beds to the fish tank, and to complicate matters there is a third sump tank to keep the water level in the fish tank stable as the grow beds fill and drain.  

Partially Completed Aquaponics System

I completed a lot of the plumbing work today, and it was not as difficult as I had feared.  I am still waiting on the arrival of the fish tank and sump tank, so it will be at least another week before I can add water to the system and see if it actually works as expected (hoped).

I am having a fun time with my family discussing what to grow.  There is a lot of trepidation about eating fish we grow ourselves (e.g. trepidation about killing and cleaning the fish).  I have been told I am in charge of converting the tilapia in the fish tank into filets on the dinner table.

There is more enthusiasm for growing fruits and vegetables.  My son Will wants exotic tropical plants like dragon fruit, which I am not sure are feasible.  My wife and I are excited about fresh herbs and salad fixings.  My daughters want strawberries.  I am very curious to discover just what is feasible.  

The next step will be installing the fish tank, sump tank and grow media.  Then of course buying fish and planting plants.  I hope to have everything finished by Christmas.