Let's talk bugs...

In looking over the spreadsheet I posted I now remember that I had quite a time with caterpillars last fall. Last year was kind of unusual for us weather wise around here. It was very dry throughout the summer, which in itself is not all that unusual. However, when we did start getting some rain it was pretty late in the year. Additionally, we had a prolonged "indian summer", which is the inevitable late season warm spell that generally punctuates the transition between summer and fall around here. With the combination of the two the critters seemed to think that spring was early and my nice leafy greens were one of the few games in town.

So, how the neck do you keep the caterpillars from ravaging your crops without dumping a bunch of toxic crap into your system?

One of the most effective controls I have found is Neem oil. Neem is a plant that is known for its antibacterial properties and is widely used in some parts of the world as an herbal remedy. The bugs, however, find the oil of this particular plant to be distasteful. I purchased a small bottle of Neem oil at my local organic gardening store. Every few days I would put about a cap full in a small spray bottle with a bit of liquid soap as an emulsifier and gave it a good shake. I would then spray the leaves of the plants.

It doesn't kill the caterpillars, it just makes the plants distasteful to them so they go elsewhere for food. It  was pretty darned effective as well as environmentally friendly.

So... about water quality...

Once you get your system set up, you have your media installed, and you have hooked up a pump to recirculate the water you need to let it run for a week or so to let the good bacteria build up and generally let the system settle.

You want to keep your pH around 7. You also want to make sure that your ammonia levels don't rise too high as ammonia is toxic to the fish. It's a good idea to invest in a good test kit to check your water chemestry. You can usually find a suitable kit at your local fish store.

For the first few months I was pretty religious about checking the chemistry every day to understand how the system was working. Turns out, once it was up and running well the readings were pretty darned stable.

Here's a link to a google docs spreadsheet with all of my chemistry readings for the first couple of months in my first system.

Heres a picture of the system just after I got my first plants in.

The first round of plants were mostly vegetative. Things like lettuce, kale, and cabbage. You can see what I harvested while I was keeping records by looking at the "Harvest" tab in the above spreadsheet.

Here's what the garden looked like in July:

Don't know if you can see all the different plants in your browser, but the tall ones are okra. There is a really nice eggplant on one side and a spaghetti squash trailing down the other. In the back there is some climbing spinach as well as a couple of patio tomatoes and a really nice basil plant.

Ebb and flow systems

There are several methods to create an ebb and flow cycle in your system. One of the simplest is to purchase a programmable timer to hook up to your pump. Assuming you plumb the system such that the water flows into the grow bed from the bottom, the timer will cause the grow bed to fill when the pump is active and the water will trickle back through the pump and into your fish tank when the pump is not active. The down side is that timers can be expensive and adds a bit of technology into the mix. The up side is they are pretty darned reliable and easy to use.

One thing to note with timers is that you will need to put some sort of overflow/outflow mechanism to prevent over filling. The water needs to have a path to drain back into your fish tank at the maximum height of your grow bed so that even if the pump keeps running you will  not overflow the sides of the bed.

Bell siphons are another low tech way to implement an ebb and flow cycle. Basically all a bell siphon consists of is a small pipe that sticks up from your main outlet and is cut off just below the maximum height you want your water level. A larger pipe with holes in the bottom to allow water in is placed over the smaller pipe. When the water level reaches the top of the outflow pipe it will begin to spill over and create a suction. This suction will be maintained until the water level falls below the holes in the outer pipe and the suction is broken. The cycle then starts over again.

A couple of items of note:

Bell siphons generally work best if you "neck down" the bottom outflow pipe to a much smaller diameter pipe. The reason for this is that you need to keep the outflow pipe completely at capacity otherwise the suction will break more easily. So... if the top of the outflow is larger around than the bottom there won't be a problem keeping the smaller pipe at the bottom supplied with sufficient flow to keep it full.

Also, you need to make sure that your inflow is *less* than the capacity of your outflow pipe. If you are putting more water in than can drain out the bell siphon your grow bed will never empty so it can't complete the cycle.

In short... the bell siphon is a bit of a balancing act, but IMHO well worth the effort.

Here are some illustrations:

Ok... so some of y'all might have noticed that in the above video the pipes on the bottom of my outflow are the same diameter as the top part that controls the maximum water level. While this works, I found from trial and error after filming this that reducing the bottom part of the outflow to a considerably smaller size was much more trouble free.

So... there you have it...

Enjoy!

Ok... let's talk types of setups.

There are two basic methods for supporting the plant and providing space for the roots:

Media based systems - A media based system uses some sort of soilless mixture as a substitute for dirt in which the plant roots can grow and support the upper part of the plant.

There are any number of types of media one can use ranging from expanded clay pellets (marketed to the aquaponics market as "Hydroton") to pea gravel. The two things you have to concern yourself when setting up a media system are weight and PH neutrality. Hydroton is ideal in that it is relatively lightweight, reusable, and PH neutral. The down side is it costs an arm and a leg. Pea gravel works quite well, is cheap, and readily available. The down sides are weight (a cubic yard weighs more than a tone) and you have to be careful about content. All rocks are not created equal. Limestone, for example, will slowly break down and raise your PH so you will have to constantly monitor the water and compensate.

Raft systems - This is basically a sheet of foam insulation that will float on top of the water with holes in it. You place a small cup with spaces through which roots can grow in those holes with a small amount of some sort of media in the cup to support the plant stalk. The up side is it is cheap,  very easy, and lightweight. The down side is it is less flexible as you are limited in where you can plant to where you cut the holes. Also, since it has much less surface area that the water runs across it does not provide as much filtration nor as much area for the good bacteria to grow on.

Water flow

There are also two basic types of water flow

Constant flow - In a constant flow system the water runs in a continuous stream through your media or under your raft

Ebb and flow - In an ebb and flow system the water is allowed to fill up to a certain point then drain out in a cycle ideally lasting somewhere between 15 minutes and an hour. The plus side of the ebb and flow system is that with each ebb cycle you pull air down into your media which keeps the "bad" anaerobic bacteria at bay. The down side of the ebb and flow is that it adds a small amount of complexity to the plumbing.

Which is better? Ebb and flow vs constant flow... Media vs raft...? Well, this is the stuff of religious debates. I can only say give each a try and decide what is best for you.

Before I go rambling.... erm... blogging about the day to day "what's going on in my garden" stuff, heres a bit of info about the construction of my first two systems. I built these systems out of a couple of these:

Just a side note about these sorts of totes. You should find out if you can exactly what they were used to haul before you bought them. These types of totes are often used to haul some pretty nasty stuff. This particular one was used to haul agave nectar.

Step 1: Cut the top off...

Step 2: Add a couple of fittings for a drain:

One of the great things about the IBC totes is they already have a nice plastic fitting in the middle that standard PVC parts available at your local hardware store will fit nicely into. For mine I put a short downspout with a couple of longer horizontal tubes with small holes drilled that will aerate the water for the fish as it trickles back down in the tank;

Note: For a constant flow system larger pipe works well. However, for a bell siphon (we'll talk about these in a future post) you will want a smaller pipe to create sufficient suction.

Here's how I plumed this particular tank:

Step 3: Make yourself a base to set the top on.

Basically this consists of a chunk of plywood with a hole cut in the appropriate spot.

Step 4: Put the tank on the top and hook the plumbing up underneath.

In our next episode... the magic of the bell siphon....

So... where to start?

Last fall I ran across a gardening concept known as aquaponics that was totally new to me. Living in central Texas, one of our main challenges is water, especially during those long hot summer months. I read this article about a technique that recirculates water in a closed loop and uses only about 10% of the water needed for traditional gardening. After receiving yet another gazillion dollar utility bill from the city the thought of cutting down on water usage but still being able to garden piqued my interest.  

At first I the more widely known technique of hydroponics in which one mixes up a bunch of nutrients in a water bath like some mad chemist growing "franken-veggies" in the lab came to mind. However, as I read further I quickly learned that aquaponics takes the whole nutrient bath concept one step further by allowing mother nature to do the job of creating the nutrients for you. 

I thought to myself, "Wait a minute, you mean that I can use 90% less water, not have to worry about constantly mixing up nutrient brews, and on top of that you don't need anything more elaborate than a couple of containers, some PVC pipe, and a water pump?" COUNT ME IN!

So what exactly is "aquaponics"?

In short, aquaponics is a system that consists of a fish tank, a container of some sort to hold your plants, some sort of PH neutral medium to support the plant roots, and a pump to circulate the water. It's basically a mini-ecosystem that works like this:

• The fish do what fish normally do in the water
• There is a pair of bacteria that go to work on the ammonia the fish produce
• The first bacteria converts the ammonia to nitrites
• The second bacteria converts the nitrites to nitrates
• Plants thrive on those nitrates and in return removes them from the water, essentially cleaning it for the fish.
• Extra credit if you throw a colony of worms in the plant grow bed to take care of the solid waste from the fish that will eventually build up and have to be rinsed out of your media.

Too darned simple, it's got to be more complicated than that! Well, that's what I thought. I've now been doing this for just under a year. I started with two small systems made from recycled "IBC totes". In that short time from those two small systems I have enjoyed:

• All of the salad greens I could eat for a few months
• A couple of varieties of peppers
• Kale
• Cabbage from which I made some excellent homemade sauerkraut
• A couple of varieties of squash
• Basil
• Climbing Spinach
• Eggplant
• Okra 
• Tomatoes grew well, but with a thriving garden comes other opportunist critters, one of which kept picking the fruits just as they started to ripen

Keep in mind here that we are only talking about a couple of puny less than 4'x4' grow beds here! As a bonus I have also enjoyed some fresh Talapia grown in the fish tank.

I have been gardening all of my life and can honestly say that this is by far the most productive and lowest maintenance garden I have ever grown. Everyone who has seen it tells me I need to start a blog. So... here it is. As time goes on I will post pictures of my first couple of beds as well as document my progress in expanding the system with an eye towards totally "transfarming" by backyard into an elegant and edible landscape.