Bell Siphon Construction and Principles

Bell Siphon Construction

 

A bell siphon is an “easy” way to drain a grow-bed in a aquaponic or hydroponic system. The idea is that in an ebb and flow system, you have a tank of fertilizer (for aquaponics its a fish tank) and a grow bed full of plants. You then pump the fertilizer into the grow-bed and the plants eat. The problem is that you cannot generally have the plant roots submerged in water all the time as the roots will rot. And you have to have a means to empty the tank so it does not overflow.

A bell siphon solves this problem very simply, with the added benefit of working without additional energy input. This is the coolest part about my system. A bell siphon works on the physics principles of atmospheric pressure and vacuums.
A bell siphon is basically three pipes. the first is a stand pipe that passes through your grow bed. When planning, it is important to understand that no water will get higher than the top of this stand pipe, and the fitting needs to be water tight. Coming out the bottom of your grow bed, you need to attach a 90 elbow to the standpipe. To this elbow, you need to glue a length of pipe of sufficient length to reach to your water tank. Finish this off with another 90 degree elbow pointing down. This is important, as you will not be able to get your siphon working properly without those two 90 turns.
The next pipe forms the bell, it is a little longer and twice the diameter of the stand pipe. One end of the pipe needs to be airtight. The simplest thing is to use schedule 40 PVC and just glue on an end cap. The other end of the bell pipe needs to have slits cut into it to allow water flow. The way I made my slits was that I leveled the saw on the end of the ball pipe, and made a short cut a little off center, and another the same distance off center in the other direction. Then I took a pair of pliers and snapped off the pcv between the cuts, leaving a small gap between the cuts. Because I leveled the saw on the pipe, I was able to make enough cuts at the same time that I had a “toothless” look on both sides of the pipe. I then turned the bell 90 degrees and repeated the process so I had 4 gaps to allow water flow into the bell. Don’t worry if this is confusing the video will show the bell.
Next I drilled a hole in the end cap and inserted a plastic 90 degree hose barb elbow. on the outside of the bell, I pushed a piece of aquarium air line on the other end of the barb. This allowed me to have an air hose running down perpendicularly to the bell. This hose needs to be fastened to the bell (I used flex ties) and have a completely airtight connection to the bell. The open end of the hose needs to be slightly above the top of the teeth cut into the bell.
After you set the bell over the standpipe so that it fits nicely over your bulkhead fitting, and the teeth are properly sized to allow water to flow into the bell, you need to create a gravel guard. If grow bed medium gets inside your bell or clogs the notches cut into it your siphon will not work. I used a PVC pipe cut bigger than my bell and slightly taller than it also. I then drilled several holes in the pipe, as water must be able to flow easily through it, but keep in mind the holes have to be small enough to keep out the medium.
Once you fill the tank you might need to tweak the system enough to get everything running, but once working properly this is a great way to drain your grow-bed.
For those scientifically inclined, this works because as the water rises in the grow bed, the air in the stand pipe is forced because the water is rising inside the standpipe by the same amount. Once the water level rises over the top of the standpipe the water begins to drain down. The 14 pounds (approximately) of atmospheric pressure presses on the water in the grow bed and push it down the standpipe. The closed end of the bell protects the water inside the standpipe from the weight of the atmosphere, which creates a low pressure zone.
At the same time, the weight of all the water running out of the standpipe, coupled with the two 90 turns keeps air from entering the wrong end of the standpipe. This creates a vacuum, and coupled with the high pressure outside the pipe, and low pressure inside the bell, the water in the grow-bed is sucked up into the bell, this allows the water to reach the standpipe even when the water level in the grow-bed is much lower than the water level inside the bell.
This vacuum exists until the end of the air hose attached to the bell is above the level of water in the grow bed. When that happens, air is sucked into the siphon with a loud slurping sound, and the low pressure is equalized and the suction stops.
As long as water is pumped into the grow-bed this will happen over and over.

Read More..

Super Greens are Super Food

Super greens and power greens.  They are all the rage with foodies and nutritionists alike right now.  Everyone is crazy for kale.  I like kale as much as the next person (I even have loads of it started right now) and I have high hopes that kale can be my next chard.

By "next chard" I mean a plant that sprouts easily, thrives in the aquaponic environment, and produces an abundance of edibles.  Since the fall, we have been enjoying an abundance of chards.  We have the traditional Fordhook chard as well as the Bright Lights colored Swiss chard.  As usual, the seed from Southern Exposure had a germination rate of almost 100%.

I admit to sprouting the chard seeds in soil and a wicking bed I rigged up, but once they hit the auqaponic systems they took off.

Chard in NFT Tubes on A-Frame

Bright Lights Chard in DWC raft

Chard in expanded clay media bed, flood and drain

While they seem to have done best in the NFT tubes, they performed well using all techniques.

I have been harvesting with a "cut and come again" strategy.  This means I dont harvest the entire plant at once.  I harvest the lower leaves and the plant continues to grow from the top.  This explains the odd growth pattern you may see in the pictures. The stem may start growing a little crazy, but the plant continues to produce new leaves and that means more for us to eat.

It means so much to eat that I have been stretching my culinary capabilities to find new uses for chard.  Chard pizza anyone?  It was actually quite tasty.  I wilted the red chard before baking it on the pizza.  Chard frittata?  It made a yummy brunch.  Of course sauted chard, boiled chard, chard wilted with bacon, chard and cornbread. Chard has made its way into just about everything but the Cheerios.  But if they keep going this strong, the Cheerios might be next.

Seriously, if you are going to the trouble to grow your own food, why not make it something that will pack a nutritional punch.  Chard has at least 13 flavonoids. One of the primary flavonoids found in chard is syringic acid. Syringic acid has recently received special attention due to its blood sugar regulating properties. It has been shown to inhibit activity of an enzyme called alpha-glucosidase. When this enzyme gets inhibited, fewer carbohydrates are broken down into simple sugars and blood sugar stays steadier.  This is important to anyone that is concerned about diabetes, weight control, or eating low on the glycemic index.

Chard also is rich in betalains, just like its cousin the beet.  This phytonutrient has antiinflamatory, antioxident and detoxification properties.  Chard as a beauty product?  Sure, if we are what we eat, why not eat something rich in vitamins A and K so that healthy skin starts from the inside. Chard packs a punch of vitamin C as well.  If you are fearful of the oxalic acid found in chard, be aware that it is concentrated in the stems.  So, all you have to do is add the stems first (so they will cook longer than the leaves) as heat destroys the oxalic acid or if you are eating the chard raw, just discard the stems. 

Got any good chard recipes?  What is the super survivor in your garden right now?

Read More..

An Unfortunate Choice of Words for the Local Holiday Food Drive

At the risk of being called a "Debbie Downer" during this time of giving, I feel I must add my two cents to the otherwise noble effort by a group of businesses to partner with Roadrunner Food to collect non-perishable food items during the holidays.

The image on the left is a scan of the paper bag that was inserted in between the various sections of The Albuquerque Journal  this week. The paper bag presented a misleading message to the public:"Solve Hunger" by donating food. A better word would be "Help Alleviate Hunger."

To actually solve hunger, we must solve some of the structural problems that cause hunger, one of which is poverty and related factors like unemployment, underemployment, low wages, lack of access to affordable and nutritious food, a high level of debt and other causes. There are 50 million of our neighbors who do not know where their next meal is coming from, including 360,000 in New Mexico who are at risk of hunger.

"Despite the end of the Great Recession and a falling unemployment rate, the nation continues to be plagued by a very uneven recovery; low employment rates; stagnant wages; inadequate public investments; and inadequate public safety net programs. Yes, there has been progress. But it has been too slow," the Food Research and Action Center (FRAC) said in its recently unveiled Plan of Action to End Hunger in America.

And how much difference does the food drive make?  It certainly helps increase the amount of food available to Roadrunner Food Bank and all the Feeding America affiliates around that country. That is an important reason why we all should participate in this holiday drive. Go to your local grocery store (instead of emptying your pantry) and buy $10 or $15 worth of non-perishable food items and leave them by your mail box on Saturday. Or better yet, take them directly to your nearest post office.

"More than half the households in New Mexico have to make really tough decisions every day," said an editorial in todays edition of The Albuquerque Journal, one of the sponsors of the food drive.  "Sixty-one percent choose between spending on food and utilities. Sixty-six percent between food and transportation. Fifty-nine percent between food and medical care. Forty-eight percent between food and housing. But there’s an easy choice more fortunate New Mexicans can make today and Saturday. That’s to fill the brown grocery bag in Thursday’s Journal with nonperishable food,"

The brown paper bag also contains some handy tips to help Roadrunner Food Bank, including signing up for programs where retailers donate a portion of your holiday purchases to our local food bank. And you are also given an opportunity to text a donation.  Here is why the financial donations are important.

"Feeding America, the nation’s largest hunger relief organization, annually serves 46.5 million people across the U.S. through its network of 200 food banks, according to its "Hunger in America 2014" study," said an article The Huffington Post. "But what you may not know is that these organizations have limited resources themselves. While approximately 100 million pounds of food is donated to Feeding America food banks each year via canned food drives, these items alone won’t solve the issue of hunger that so many Americans face. Tight budgets, limited volunteers, finite donations, and the short turnarounds required between receiving fresh foods and distributing them to families in need can be challenges in addressing the issue of hunger – and doing so with nutrient-rich foods."

The holiday food drive should give us at least a small opportunity to show solidarity with those who receive the food. One way to do this is to be aware of the reasons why families are in their current predicament.  It doesnt help when the campaign tells us that we are actually solving hunger through our holiday donations.

Read More..

Modern Design System

The future design

Aquaponics, ækw??p?n?ks, pisciponics

Read More..

EFB ACK!

Earlier this summer, we noticed our new package of bees wasnt building up as quickly as it should, and the brood pattern wasnt full and solid like it would be in a healthy colony.  We started looking closer at the combs, and noticed a few things.  Most of the uncapped cells all had eggs or larvae in them, so the queen was laying fine.  But many of the uncapped larvae didnt look quite right--some were sort of discolored and laying at the back of the cells; others started to extend out toward the front of the cells, but were slightly twisted, as if they had a stomach ache. In short, a lot of our brood frames looked like these and these.  Sounds like trouble.  Not trusting our limited beekeeping experience to officially diagnose the problem, we decided to send a comb sample to the USDA bee lab, where they test it for free and tell you what disease your bees have (if any).  A few weeks later, the results came back: our bees had European Foulbrood (EFB).  Oh no!

Heres the old brood comb, with the sample we cut out to send to the Bee Lab.  Although they only ask for a 2" x 2" square, we cut out a section to fit a small USPS box instead.  Dont want them to wish they had more to test!

So what are our options for treatment?  While EFB is no walk in the park to get rid of, its not quite as bad as its evil sibling American Foulbrood (AFB) in that it doesnt form spores.  For AFB, the only treatment is to kill the bees and burn them along with the frames and comb (hive boxes and other equipment the bees have come into contact with can sometimes be sterilized by high heat or bleach).  For EFB, there are a few more options (and here):

1. Do nothing, since in a strong hive, symptoms will often clear up when the nectar flow is strong.
2. Treat with the antibiotic Oxytetracycline (trade name Terramycin).
3. Re-queen, since a disruption in the brood cycle will often clear up symptoms.
4. Use the "shook swarm" method to restart the colony on uninfected combs in a new hive (this also disrupts the brood cycle).
5. Kill the bees and burn or sterilize everything, same as for treating AFB.

Of these options, we had already been trying #1 for a while, and it clearly wasnt clearing up.  Were trying to minimize chemical treatments of our bees, so #2 wasnt a great option, either.  #3 would be ok, but it seems like we could get the same effect by #4, which was preferable to us since our queen seemed to be laying well and we already had everything we needed.  #5 is obviously a last resort, and we werent there yet!

So, shook swarm it is!

The general operation is simple, and shown here: were just taking all the bees from the old hive and shaking them into the new hive.  A few tricks that arent shown in the video: the new hive should have a queen excluder on the bottom (actually functioning as a queen includer) so that she doesnt have the opportunity to decide she doesnt like the new digs. Also, the chances are good that shell end up in the new hive if were efficient in our shaking operation, but we can increase the odds by spraying the frames down with sugar water to reduce flying bees before shaking them, or if we wanted to be really sure, we could find the queen and catch her, and then install her in the new hive once the rest of the bees are in there.

Also, in our case, since were trying to clear up EFB, the new hive should just have foundation and not already-drawn comb so that the bees have a chance to sort of purge their system before they have to feed new brood. Some sources recommend holding off on feeding them for a few days for the same reason.

After a couple weeks in the new hive, theyve started drawing out comb and generally looking healthier.  Can you find the queen in this picture?  Her name is Waldo.

If we blow a little smoke on them to clear the bees away, we can see that the brood pattern looks a lot more full than it did in the old hive.  Time will tell if they can build up enough to make it through the winter, but theyve got a better chance now than they did before!

Stay tuned to find out what happened to all the old frames, comb, and the honey they had stored.

Have you dealt with EFB before?  Have you done the shook swarm method with your bees?  How did it go?  Let us know in the comments section below!

Read More..

Franciscan Father Richard Rohr Discusses Laudato Si

Shane Claiborne and Richard Rohr

Listen to Father Richard Rohrs talk on Pope Francis Encyclical Letter on the Environment, Laudato Si. Rev. Rohr presented the talk at the Francis Factor conference in Albuquerque on Aug. 30-Sept. 1. The audio comes courtesy of the Center for Action and Contemplation.

Read More..

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...

Read more »

Read More..