Aquaponics Garden Part 7 – Early days


20131229_165609The aquaponics system has been running for 12 days now and I have a few observations. I added four more goldfish to the tank today, bringing the total up to eight. Double the fish, double the poo! Yay! We get our fish from the feeder tank of the aquarium store, but they are really nice looking fish. They are Comets, which have larger fins than common goldfish, and they have lovely colours and patterns. They aren’t “fancy” goldfish, which is for the best, because they don’t have exaggerated body shapes or bulging eyes that could make them less hardy. The plan is to have 12 all together, which we should have in another week or so, providing the water conditions hold. I’ve been testing ammonia, nitrites and nitrates daily to see whether the nitrifying bacteria I wrote about a couple of posts ago have moved in. As of yesterday, there is no measurable ammonia in the water, so I am thinking that the filter media from Madeleine’s mature aquarium helped to speed up cycling the system. There is also no measurable nitrite or nitrate yet, though it is possible that the plants have sucked it all up. Speaking of plants, you’ll notice a couple of spiffy new fake plants in the fish tank. They provide a bit of shelter for the fish and jazz up the place.

20131228_155926I thought the basil leaves were looking somewhat yellow, so I added some more liquid seaweed to give the plants more nutrients. This gives the water a greenish tinge, but doesn’t appear to have any effect on the fish. At this early stage, everything is on the edge: the plants do not really have enough food because there aren’t many fish and they are small, but if there were more or bigger fish, the water quality would be dangerous for them. I just have to wait for the nitrifying bacteria to fully populate the system so that both the fish and plants are happy. By starting with small fish and small plants they can grow up together.
20131228_160006Most of the seeds I planted have germinated, though nothing has got as far as having true leaves yet. I had to pull the thyme plant I got from the grocery store. It didn’t look like it appreciated having a warm bath a few times an hour and I suppose not all plants do.

Some of the expanded clay balls have developed white hard water deposits on them. I don’t think I’ve seen that in any images of other aquaponics systems, but I can’t imagine it would be a rare thing. We have quite hard water in our well, and the ph is also high.  Just as in soil gardening, the ph of the water affects how nutrients are absorbed by plants. Most plants  would prefer a ph of just under 7, but ours is 8.3. I’m waiting to see what happens with it, because nitrification has a ph lowering effect on water. Most aquapons (people who do aquaponics) seem to have difficulty keeping their ph high enough. Now that the system appears to be cycled, I will be curious to see whether the ph drops. The high hardness does have a buffering effect on the ph, which means it may stay high for a while before I notice any difference.

For the next while I’ll be monitoring water conditions and plant growth in addition to fish and siphon watching. It’s all very addictive.


Aquaponics Garden Part 6 – Shedding some light on things


The homemade fixture which has a total of 8 T8 tubes.

One of the main design considerations that I struggled with when thinking about my aquaponic garden was what kind of light to use for my plants. I knew that if I was serious about growing plants then I would need serious light, but serious light can have serious costs both to purchase and to operate.

Some of the options currently on the market are LED, induction, metal halide, high pressure sodium and fluorescent. All have advantages and disadvantages, and everyone will weigh them differently depending on circumstances. A primary consideration for me was purchase cost, as I am definitely suffering from aquaponic shopping fatigue. Also, I am planning to move the garden to an outdoor bioshelter in the next year, so I can’t amortize the cost over many years. That ruled out LED and induction, even though they both have very high “cool” factors, literally and figuratively. The standard grow op lights, the metal halide and high pressure sodium, are moderately expensive and run hot, so typically require some kind of cooling in addition to the light. They are pretty much the standard, though, having been used for years to grow countless pot plants.


The two 125 Watt compact fluorescent fixtures.

I decided to go with fluorescent for a few reasons. I am planning to grow mostly greens and herbs, rather than fruiting or flowering plants. This means my lighting requirements are not quite as high as if I was trying to get my pot plants to flower, or produce cucumbers or ripe tomatoes. I also already own four standard tube-style fixtures, with bulbs that were used for only a few weeks last year. I found two 125 Watt compact fluorescent bulb fixtures with bulbs included for $70 each on Amazon and bought them without a clear plan of how I would configure them. Initially, I hung one over each grow bed, but it was clear that the ends of each bed were simply not receiving the light they should. So today Luc and I built a diy fixture to hold all four of the strip lights, with 8 32 Watt T8 bulbs in total, to light one of the beds, while both of the compact fluorescent fixtures now hang over the other bed. The instructions for those fixtures say that the light should be from 1 – 3 ft above the plants, which seems a little vague, especially since tube lights are supposed to be just a few inches above the plants. All of the fixtures are height adjustable, so I will experiment to see what works best. Both beds are now receiving around 250 Watts of fluorescent light, which I believe is probably minimally adequate for 8 square feet.

I don’t have much experience growing plants indoors, other than seed starting and microgreens, neither of which are particularly demanding for light because I either kick them outside, in the case of the starts, or eat them before they complain too much. I am curious to see how these longer lived plants will make out.


Aquaponics Garden Part 5 – The tiny critters that make it all work

I’ve been saying that the aquaponics garden works because the plants use fish waste water as fertilizer and while that’s true, it is, like many things, a gross simplification. Fish poo and pee and also excrete ammonia directly through their gills. Not only is ammonia toxic to fish, but plants cannot actually use these things either. Luckily there are bacteria everywhere that will convert the ammonia to nitrates which plants do use. These bacteria may be everywhere, but it takes time before a sufficiently robust colony of them is established in an aquaponics system (or aquarium) so that a full stocking level of fish can be safely kept. The process of establishing this colony is called cycling.

Cycling can be done with fish in the tank or without, but I have chosen to cycle with a small number of fish. Madeleine has a healthy, fully cycled aquarium and she gave me some well used filter floss from her filter to jump start the cycling process. This stuff is loaded with the nitrifying bacteria that will colonize the grow media with its huge surface area and ultimately every surface in my system. I buried them in the grow media just under the water inlets of the grow beds. Nitrifying bacteria are pretty slow growing in bacterial terms, doubling in about 15 hours more or less, depending on temperature. The four small goldfish will hopefully provide enough ammonia to keep the bacteria fed while they are growing.

I’m doing daily water tests to determine whether the system is cycled yet or not. It can take up to six weeks to cycle from scratch. So far, I have not detected any nitrites or nitrates, and only barely detectable levels of ammonia. Since there will be a period of time before nitrates appear, I have added liquid seaweed to the system to provide nutrients to the plants, and a small amount of ammonia for the nitrifying bacteria. I’ve been heating the water in the tank to 23C, for the benefit of the bacteria, though the fish and plants are fine with it, too. Goldfish are able to tolerate a wide range of temperatures, a real advantage in terms of fish suitability for an aquaponic system, but for now they get to enjoy the warm bacteria-growing water.

Getting the system cycled is my immediate goal as it is the key to happy fish and plants. As an aquaponics gardener I am basically a bacteria farmer. If I can keep the bacteria happy, everything else should fall in place.

Aquaponics Garden Part 4 – Going live

20131220_171117Construction of the aquaponic garden is complete, at last. We (and by we, I mean my husband with moral support and fetching from me) designed, built and installed the tank covers today. After a couple of days of running the system without them, it was pretty clear that covering the tanks would reduce evaporation, humidity in the basement and some of the water sounds. We bought a few of those clear polystyrene lighting panels that go in suspended ceilings under strip fluorescents. They’re very brittle, but not very expensive, and Luc was able to cut them to size without breaking any. They are very light so they are easy to remove to get access to the tanks.

20131217_161845#1A few days ago, I planted a bunch of things in the grow beds. The plants that are visible in this picture, taken shortly after, are what I call the produce-section garden. I bought a couple of potted herbs, some green onions and a bunch of celery. I rinsed the soil off the herb plants and stuck them in the media. They were in pathetic condition at the time – suffering from not enough light or water, and in shock from the brutally cold temperature between the store and car, and car and house. They do seem to be enjoying the nice warm water bath they receive every ten minutes, and I think they’ll make it. The onions and celery were rather unceremoniously jammed in the media after I cut their tops off, and they are both sprouting new tops like gangbusters.  I sprinkled some seeds around the beds, and today I noticed that the brassicas, lettuce and swiss chard had germinated already. This is very easy compared to dirt gardening, not least because everything is at waist level, but also, well, the lack of dirt. And this is from someone who has a rather overdeveloped respect for soil and all its inhabitants.

20131219_185233The most recent additions to the aquaponic garden are these four beauties. These are actually the first four of a dozen or so goldfish that will eventually occupy the fish tank. My daughter Madeleine is acting as the fish consultant for this project because she is a fish nerd and also works at an aquarium store, so I trust her judgement and advice. She has been quite stern with me that we are not to stock the tank too heavily at first, in order to ensure the welfare of our piscine friends. Which brings us to cycling, which deserves a post on its own and is for next time.


Aquaponics Garden Part 3 – Just add water

Another exciting day in the basement! Yesterday we got the whole system put together and today it was time to wipe down all the tanks and add some water. As expected, there were a few minor leaks that we were able to stop, and no doubt we will find more as the system starts to fully operate. So far we are flood free.

The most exciting part of the day for me was testing the bell siphons (also known as autosiphons). Ever since I first started learning about aquaponics, I have been slightly intimidated and impressed by them. According to quite a few folks, they won’t work right the first time but will work forever once they are correctly set up.  These are mysterious gadgets that allow the grow beds to continuously fill, while periodically draining at a much faster rate. This is called a flood and drain system, and it ensures that plant roots have access to moisture and nutrients but also are exposed to a lot of oxygen. The media the plants are growing in consists of small marble size balls of expanded clay, which leave lots of air gaps so that plant roots will never be water-logged.


The standpipe, which is simply an end of 3/4″ pvc conduit piping with a 1″ opening.

A bell siphon consists of a standpipe, the height of which determines the maximum water level in the bed, and a “bell” or in this case, a pipe with a closed top and openings in the bottom which come up to the minimum water level in the bed.


The bell is a length of 2″ pvc pipe with slits cut up to about an inch from the bottom.

Water enters the siphon through the openings in the bell, until the height of water in the tank is at the top of the standpipe. At that point, water starts to drain over the top of the standpipe, eventually filling the pipe and excluding air. At this point a siphon is formed, and just like you can steal gas from a car, you can drain most of the water out of the grow bed, until it reaches the level of the openings in the bottom of the bell. If you’ve stuck with me to this point, you may want to have a look at this video, which explains it rather well.

The siphon in the video has a separate tube which accomplishes the same thing as the slits in the bottom of my bell. The siphon is protected from grow media and plant roots by a larger perforated tube. I was very impressed that the siphon ran fine on the first try, but I’m a little nervous that it shouldn’t be so easy. I actually took a video of the end of the draining, which was amusing for me, but likely not for you, so I refrained from sharing it.


This is what all the excitement is about. The bell siphon is working as advertised and draining the tank into the sump.

Next up: rinsing dust and debris off 100 gallons of grow media and filling the beds.

Aquaponics Garden Part 2 – Putting it all together

Finally, we’re at the fun part – putting it all together. It’s all assembled now; there were a few frustrating moments and a couple of hardware store runs, but all in all, it went rather smoothly.

It started by drilling a hole in the bottom of a grow bed and installing the bell siphon. That first hole was a bit nerve wracking, but using the right bit made all the difference in getting a clean hole with no tearouts. I’ll talk more about the bell siphon in another post.


The “bell” of the bell siphon: a 2″ pvc pipe with a cap on the top and slits cut in the bottom.

It took several hours to get to this point ( I know, I know, that comment I made in the last post about projects taking twice as long as expected was way understated). The two grow beds are each equipped with a bell siphon and media guards (designed to keep the expanded clay balls and plant roots out of the siphon) and drain to the sump tank.


The grow beds with their siphons and drains into the sump tank.

Things went a little faster when installing the fish tank drains. There are two separate drains in case one gets clogged. They are simple pipes that are open at the top so a siphon does not form (we do not want the fish tank draining itself dry) and have large openings in the bottom to draw water and fish waste from the bottom of the tank. This should keep the fish waste from accumulating at the bottom of the fish tank and allow it to be distributed to the plant beds, where it will be broken down into plant nutrients.


This is the last hole being drilled through the tank walls. A bulkhead fitting is inserted and the 3/4″ pipes are friction fit to it.

I like the tidy look of the tanks and their drains, but there is more to come.


We decided to use 5/8″ drinking water-safe garden hose for the supply lines. Apparently, most garden hoses contain lead, which means I am surely suffering from lead poisoning, and which might explain a few things. Anyway, our fish and plants will not be subject to lead hose. Using a garden hose allowed us to use a garden hose manifold valve, and it seems like it might make things slightly easier to adjust than using fixed pipes.


The garden so far.

The hose manifold valve has water entering from the pump in the sump tank, and exiting to the grow beds and fish tank. The middle two outlets go to the fish tank.


Close up of the water distribution hoses and valves.

Next on the to do list: testing the bell siphons and the entire system for leaks. Stay tuned!

Aquaponics Garden Part 1 – Ready to assemble


It’s taking a little longer than expected (first rule of project management – it will take twice as long as you think) and costing a bit more (second rule of project management – it will cost twice as much as you think), but the aquaponics project is ready to put together. It’s a bit overwhelming to look at all these bits and think about all the little things that need to be done to them to herd them into some kind of order. I’ve spent lots of time on websites and youtube, and reading aquaponics books, but I’ve never actually seen a system in operation in real life. I am not following any specific plans, but I’m not straying far from some that I’ve seen. Inevitably, I will figure out better ways of doing things, but with the naive confidence of a complete novice I think I’m on the right track.

The shopping has been interesting. I bought the stock tanks at a farm store, the expanded clay grow media at a hydroponics store, a bunch of stuff like a heater, grow lights, a water pump, and an air pump on Amazon, some more grow media from a guy on kijiji, and a bunch of plumbing bits and various hardware stores in the area. If my recent browsing history hasn’t put me on some kind of watch list, my purchases surely have.

Tomorrow we (oh yeah, I’ve enlisted some very competent help for this project – I even had the foresight to marry him 23 years ago, so he’s kind of stuck with it) start putting it all together. We’ll be assembling a couple of bell siphons, which I’ll explain in a future post, but which use the laws of physics in a way that I’m eager to see in operation. Luckily we live only a couple of kilometers from a well-equipped hardware store, so if it turns out my shopping list was incomplete we should be able to get what we need without having to mount a huge expedition.

Gold fish and green plant grow op.

So this is my latest project. I’m setting up an aquaponics garden in the basement and I’m very excited about it. Aquaponics uses water from a fish tank to fertilize plants. The plants take up the nutrients in the fish waste that would otherwise pollute the fish tank, resulting in clean water for the fish and nutrient-rich water for the plants.

There is a 100 gallon stock tank that will hold a dozen or so goldfish, 2 50 gallon stock tanks that will hold the growing media and all the plants, and another 50 gallon tank that will be the sump tank, containing the pump that will distribute water to the entire system.

This is a pretty big indoor setup, and the learning curve is pretty steep, but I’ve been enjoying the research and planning phase. The next step is to assemble the components and test everything before installing plants and fish. I’ll be posting pictures as I go.