Expanded Shale for Hydroponics and Aquaponics

A little self promotion for my company....

Bigelow Brook Farm is pleased to announce a new partnership with The Aquaponic Source as a distributor for our expanded shale product line. The Aquaponic Source (www.TheAquaponicSource.com) specializes in a wide array of products providing complete solutions for the North American home aquaponic gardener. Along with their on-line store, they also provide an active and free community site filled with a vast array of aquaponic discussion topics and information for both novice and experienced users at www.AquaponicsCommunity.com. “We are extremely excited to be working with Bigelow Brook Farm and offer expanded shale to the aquaponic and hydroponic gardening communities. Finally there is a US based grow media with optimal growing properties!” says Sylvia Bernstein, President of The Aquaponic Source. “We think this will become a core component in the rapidly expanding soil-less growing market in North America.”

For more information about Expanded Shale, please visit our web site at www.BigelowBrook.com or www.ExpandedShale.com.

Building a Geodesic Dome Greenhouse - Part 3

Finally got around to doing the third video in my series of building the geodesic dome.  This one covers how all the struts are made.  It's filmed in HD so you should be able to expand it to full-screen!  I hope you enjoy it!

Below is the transcript from the video....

Hello Everyone,
This is the third video in the series about building a geodesic dome greenhouse.  This time I will cover how to build the interconnecting struts which are made from red cedar.   I choose red cedar because it is rot resistant.  You could use treated lumber, which is substantially cheaper, but I was concerned about chemicals leaching into the water for my aquaponic system.

The site I used for the calculations is acidome.ru.  The entire site is in Russian, but Google Translate does a fairly good job converting the text.  The calculator lets you enter the diameter of the dome, choose the hub type and size, and even the dimensions of the struts.  It will then calculate the angles needed at each hub and also calculate all the various sized struts and labels them with the dimensions taking into consideration the size of the hubs.

The best feature is the ability to have the software calculate a flat base, since a 3V 3/8th dome is not flat.  One click and the struts are recalculated with the proper lengths!

With a 33 foot diameter 3V dome, each triangle will never be wider than 6 feet.  This will allow me to purchase the polycarbonate glazing in 6 by 24 foot sheets, helping to minimize the amount of scrap.

The struts are made from red cedar 2x4’s by 14 feet.  This will be enough material to cut 2 struts from each board with some scrap.  The end of each board is cut at a 12 degree angle so it will align with the hub.  Not every hub connection is exactly 12 degrees, but there is enough flex in the structure for the angles to average out properly.

Once the struts are cut to length, they are run through the table saw to add a slight bevel to them.  When the dome is fully assembled, the polycarbonate panels will rest fairly flat along the bevel.  This will also insure that the height of each strut is the same since it can vary slightly from the mill.

Next I remove some of the material from the end of each strut using a dado blade mounted in the radial-arm saw.  This space will provide an area for the top tab of the hub to rest and provide enough clearance for the polycarbonate panels over the crown of the carriage bolt.

I built a jig to act as a stop and keep each strut aligned properly during drilling.  This allows for a consistently placed hole to be drilled near the end of each strut.  The placement of this hole is important so it will fit properly into the hub and provided an accurate length for the hub and strut combination.

And now, the perfect excuse to use one of my favorite tools!
The bottom of the head of a carriage bolt has a square neck so it can grab into wood to prevent it from turning.  To get it to fit into the metal tab, I would either have to drill the tab’s hole larger, compromising some of its strength, or turn down the neck of the bolt in the metal lathe.  I chose to turn each bolt and then will re-galvanize the area with cold-galvanizing paint.

Here is an example of how the final assembly will fit together.  The strut is sandwiched between the two hub tabs and then tightened into place using a lock washer and nut.

This top view displays how each strut can pivot slightly on each hub.  Since the angles of each triangle section aren’t the same from one section to the next, this allowed for me to make the same hub and allow the pivot against the bolt to make minor changes to the angles.

This side profile shows how the dado in the strut allows the polycarbonate glazing to clear the area without hitting the tab or bolt head.

Finally, this profile displays how the glazing will set flat into the beveled area that is cut along the top of each strut.

I assembled the base to verify that the calculations were correct and the pieces fit together.  So far, so good!

That’s all for now.  The next video I plan on detailing some of the site work.  Thanks for watching!

Building a Geodesic Dome Greenhouse - Part 2

Here is the second video in the series of building a geodesic dome greenhouse.  It covers 3 different hub designs (and failures) along with the details of how they are assembled.  I’m trying not to make them too boring, but after all, it's just a bunch of diagrams, cutting and welding.  At least you can see some sparks fly!  There’s a couple of bloopers at the end too!
 

Below is the transcript from the video:

In this video I will discuss the hub design for this dome and the next video in the series will detail the strut design.  This is 3V 3/8th dome so it will require a total of 46 hubs consisting of twenty-five 6-way, six 5-way and fifteen 4-way hubs that will be used along the base.  Because of the large span, this dome is going to need a hub that can withstand a great deal of compression force.  Plus, it must be able to withstand the downward force from heavy snow loads during the winter.

The first hub design had hanger bolts anchored into the end of each strut.  The end of each bolt would go through a hole in a piece of schedule 40 3-1/2” steel pipe which was used at the hub.  The strut was tightened to the hub with a washer and nut.  This is the first prototype using the hanger bolt method and a PVC hub.  The triangulation between each section was extremely strong.  When I created a full scale prototype, the leverage of a full length strut and removal of the triangulated pieces cause the hanger bolts to easily pull out of the end of the struts.

The second hub design was similar to the hanger bolt design, except a hole was drilled through the strut and a washer and nut was inserted.  This was to create enough surface area to prevent the bolt from pulling through the wood.  However, testing a full scale prototype proved to be too much force against the strut and the bolt acted as a level and split the wood.

The third hub design is completely different. The strut is sandwiched between two spokes.  Flat bar-stock is welded to the hub at the appropriate angles and a bolt is placed through the top spoke, through the strut and fastened with a nut under the bottom spoke. This full-scale prototype shows how 4 spokes of a 6 spoke hub would be assembled.  A load test shows it can support my body weight on only 4 spokes, plus none of the other struts are used to strengthen the legs.  There was some slight bending of the bolts from my bouncing but there was no hardware failure.  Regardless, the final design will use 3/8th inch bolts instead of 5/16th.

The central hub is made from 3 ½” galvanized rigid conduit which is about ¼” thick.  The conduit is cut into 3 ½” lengths.  The galvanized zinc is ground off wherever the spokes are to be welded.  Please note that working with galvanized material, especially using abrasion cutting equipment or welding should be done in a well-ventilated area.  Also, you should always wear gloves and safety glasses.

I made up a jig that will safely hold the bar stock to the drill press.  It allows me to consistently drill a pilot hole in the same location near the end of the stock.  Since I have 480 holes to drill, creating jigs and templates is crucial for building an accurate hub.  Once the pilot holes are drilled, I switch over to a stepped bit that will finish the hole at the proper size.  I then flip the piece over and gently remove any tear-out from the bottom of the hole.  Once the holes are in the end of the stock, I then cut it to the correct lengths.  I built a stop for my abrasion saw so I could cut each piece to the same length.  After cutting off the ends, I can go back to the drill press and drill a new set of holes for the next set of spokes.

Now it’s time to start assembling!  This template has markings on it so I know where the locations are for the 5 spoke or 6 spoke hubs.  I just place the hub over the template and draw a small mark on the hub.

This jig is used to accurately weld the spokes to the hub.  The hub is placed over the post and each spoke is held in place with a pin.  By using this jig, I can weld a complete hub in less than 15 minutes.

All the pieces are welded together with a standard MIG welder.  Another safety note:  Please weld in a well-ventilated area and free from items that can catch on fire.  Also wear the appropriate gear to avoid burns from the hot metal and use a welding helmet to prevent blindness.  Keep fire suppression equipment nearby at all times.  No one else should be in the area while using a welder.

When each hub is complete, any dirt and rust is removed by sandblasting and is then painted with cold-galvanizing paint to prevent future rusting.  I hope you enjoyed this video on making a hub for the geodesic dome.  The next video will show how the struts are made.  Thanks for watching!

Greenhouse Roof Failure!

A little mishap happened with our last snow storm.  The north facing roof buckled on the greenhouse from the snow.  From the photo, you can see that the 4 “rafter” pieces have all bent in.  The rigid foam insulation that I had installed on the inside has also pushed in.

Luckily, when I assembled the greenhouse, I had added some extra bracing inside.  This prevented it from totally caving in so it’s not a total loss.  The plants and fish are still alive!  This spring, I should be able to dismantle this section and bend the pieces back into shape….and add some additional braces inside.

Here’s a link to my blog that displays the original bracing I installed a few years ago.  Link to Blog
 

Spring can’t come fast enough!

Building a Geodesic Dome Greenhouse - Part 1

Hi Everyone! We're Expanding! We are pleased to announce that we have just received the necessary permits to build a new greenhouse. This 1200 square foot, state-of-the-art building will utilize some of our latest technology to enhance the building’s energy conservation, as well as monitor and control an aquaponics growing system. The greenhouse will be used for our research and development, and it will become the focal point of the farm as a visitor center. Construction is scheduled to start this spring and we are eagerly waiting for the ground to thaw.

This video is the first part of a series I'll produce over the next year or so. I hope you enjoy the adventure! (click on the video image to view in a new window...blogspot likes to crop these grrrrr)

Below is the transcript....I put it in here for the search engines!

Hello everyone. I wanted to welcome you to my winter wonderland. A couple days ago, we received about 2’ of snow. Here it is, I’m standing in it at about knee height. Here’s a show of the greenhouse and the garden.

One of my exciting things that I’ve been working on is to build a new greenhouse. This area down in here, which is off of one of my main fields, is going to have a 900 square foot geodesic dome, along with an out-building attached to it for heating and storage. It’s pretty exciting that I’m going to be able to build this. It’s going the be a big improvement over my 120 square foot greenhouse. This wooded site here is where it’s going to be. All the old farm equipment and trees will be moved and the ground will get leveled off.

It’s going to take me about a year to build it. I’m going to do everything from scratch – no kits at all. This is the location again – it’s just off of one of my fields we use for growing corn.

At the end of my video, I’ll also show you some of the plans for the building and some of the ideas for how the aquaponics will work too. I also wanted to thank everyone for reaching a 1000 subscriber mile mark. It’s pretty good for the aquaponics folks. Not quite like some of the millions or so that some of the other guys get on YouTube, but it’s nice to see a good group of people following along with what we do in the aquaponics world. Thanks again.

This is the site plan that was needed to obtain the wetlands permit. It shows the existing land and outlines what type of grading and the types of erosion control that will be installed to protect the wetlands that are near the site.

This particular location was picked because it was near one of the fields and needed minimal amount of excavation work.

This is the side profile of the geodesic dome. It sits on a required 4’ frost wall and will have a shed on the north side that will house a wood furnace. This also shows roughly how the grow beds will be set up.

The foundation plan shows the 33’ dome, the shed area, and post footings for an open-air shed roof which will be used for wood storage.

This plan displays the grow bed locations and how they drain into a central sump tank. The sump will pump water to the larger fish tank. This tank will have a siphon that will drain through a swirl filter and into a second tank. The second tank will be used for extra water storage as a thermal mass. The water will then be pumped from this tank back into the grow beds.

Buried under the floor will be 4” perforated pipe. During the summer months, air will be blown through these to get cooler air from the ground. Over the winter, warm air during the day will be pumped underground into the thermal mass, which will radiate back up into the dome during the nights. Hopefully the wood furnace will only be needed on extremely cold,cloudy days.

That’s all for now. I hope you subscribe to this channel for future updates. I will be showing detailed plans on how the entire dome will be built. We’re hoping to get started this spring once the frost is gone. Oh, and this is our skating ring that we love to use during the winter!

Winter in New England

18" of snow...we'll get a few more before the storm is over. It's nice to see all that money I spend on heat goes right through the roof and melts it! (sigh)

How To Build Your Own Strawberry Tower

By popular demand, here's a video detailing how I build my strawberry towers. I hope you find it helpful! Full transcript is below. Click on the video image to watch in HD!

Hello everyone.

One of the top requests I get is how to build a strawberry tower. This video will display all the necessary steps to build your own.

The first step is to place a mark on each end of the pipe, then rotate it 180 degrees and mark the other end. Then snap a line down the entire length of the pipe. You could also use a straight edge to mark a line, but I find the chalk line to be more accurate and easier. Turn the pipe over and snap a second line down the opposite side.

Along each chalk line you will place a series of marks. Starting at 2 inches, draw a mark every 8 inches. This will be the spacing between each pocket in the tower. If you are going to grow plants that need more root area, set the spaces further apart. I typically replace the strawberry plants every season. If they grow for more than one season, they can become root-bound.

Starting at the first set of marks, draw a line from one mark and connect it to the mark on the opposite side. Then turn the pipe 180 degrees and connect the next series of marks. Continue rotating the pipe while connecting each series of marks. These lines will be used for cutting the slots in the tower.

Along each cut mark, carefully cut through the pipe until you reach the measured mark you placed at the chalk line. Do not cut through more than half the pipe! Rotate the pipe 180 degrees and cut the next slot. When you are done, each slot should be on the opposite side of the previous slot.

Time for some good gloves. The pipe doesn’t become flexible until it is well above the boiling temperature of water. Please be careful!

The general area that will be heated will be an arch shape starting at one end of the slit, up about 8 inches to the back side of the neighboring slit and then back down to the other end of the slit.

Heating PVC should be done in a well vented area. If you overheat it, it can release some nasty gases. Please be careful! Continuously move the heat around the arched area. Try to avoid heating the area below the slit to keep the pipe from bending too much.

After a few minutes, the PVC will become soft. It helps to apply a little extra heat at the each edge of the slit since this is where the sharpest bend will be.

Push in the PVC so it makes a concave shape in the arched area. You will want to push it in enough so that it will touch against the back wall, but not create a seal since the water will need to trickle through that area, but don’t leave too big of a gap so your growing media will fall through it. When you let go of the pipe, it will usually spring back a little, leaving a gap around ¼”.

I found it to be very helpful to use a few spring-clamps to hold the tight bends in place while the plastic is cooling. You will want to hold the shape in place for a couple of minutes while it is cooling.

It takes me about 3 1/2 minutes to completly create each pocket.

When you are done, you will have some nice pockets alternating on each side of your new tower.

As the water flows through the tower, the surface tension in the water can cause it to flip out of the edge of the slit. To correct this, I added a collar around each pocket.

With some extra pipe, cut some rings about 1 ½” wide. Then remove enough of the ring so when it’s placed over the slit area, it extends just beyond the slit. Add some silicone adhesive and clamp the ring in place. Half of the ring should be placed above the slit line. Use clamps to hold it in place until it cures.

If you’re not going to be draining directly into a sump tank, you’ll need a way to catch the water from your towers. Take a 4” cap and add a fitting to it. Drill a 7/8” hole and thread it with a ¾” tap. There are several ways of adding fittings, but I found this to be very cost effective method.

Take a ¾” NPT to barbed fitting and screw it into the tap. If it is screwed in far enough, it will be higher than the base of the cap. This work well to help any media that as fallen through from going down the drain and clogging it.

This cross-section shows how the fitting is placed into the cap.

Place the cap on the bottom of the tower. The bottom pocket should not be filled with anything so you can clean the base cap if necessary.

To hang your tower, drill a couple of holes on both sides near the top and insert some S hooks. Use a wire or chain to hang it from a strong support.

To connect the tower drains together, you can attach them with tubing and barbed fittings. I made some stands from scrap 3” pipe to support the bottom of the tower. Then I used a 1-1/2” pipe with holes drilled in the side to catch the water from each tower. Each pipe then drained into the main sump tank.

Filling each pocket can be a challenge so I made a tray-type funnel to speed up the process. Take a section of pipe and do a cut down its length. Heat the entire piece so it can be flattened, then bend up the edges so it forms a V shape.

I created a cross-cut section so you could see the inside of the tower. Please note that this sample is done with black ABS so you could see the various surfaces easier. Each pocket will hold about 5 cups, or 1 liter of growing medium. This is enough space for most shallow root plants like strawberries or lettuce. For my strawberry plants, they will usually get water for 10 minutes every hour and a half.

Thank you for watching. Here’s a quick slideshow of my strawberry towers in action!