Plants, Plants and more Plants

Here's where my system is at going into mid May, I just got finished placing some of my left over expanded shale into the area around the pump house and barrel filters. I placed some above ground plastic edging at the boarder of the ground tarps over to the greenhouse , and then used about 3 wheelbarrow's full of shale to fill it in about 2" inches deep. I was in jeopardy of losing the weed block as it was beginning to deteriorate from the sun.

It turned out rather nice and provided good drainage for any rain water coming off the greenhouse.

I have also included a few pics of the raft system plants to show some of the growth that is going on.

I have five varieties of lettuce, which include Romain, and bibb. Just wish I had more growing.

 I also have squash and cucumber plants in the raft systems which seem to being doing "Just OK", but really haven't taken off yet.

Here is a quick overview video of the entire greenhouse setup, inlcuding the DWC Raft and new nursery plant rafts.

Until Next time....

DWC Raft construction update

OK, so I had time to make a quick video on the DWC rafts for one of my aquaponics media based growbed systems. I have finished the rafts and will concentrate on the filter system next which will allow me to tie the two types of media together into one system - DWC and Expanded shell grow beds. I will attempt to get the filter system completed within the next several days and hopefully have it completed and tested by the end of next week.

DWC on-going construction.

Hope you enjoy the video, and remember, you can find all of my videos on the Aquaponics Gardener YouTube channel.

http://www.youtube.com/user/Aquaponicsgardener

Until next time, happy gardening.

Construction of the DWC rafts

Well, spring is in the air, and you know what that means....it's time to expand the system and add the Deep Water Culture rafts to the grow beds. So I have purchased most of the materials at my local building supply chains, along with the 12mil B/W Poly Scrim liner material on-line from Americover.com. I based part of my design on the UVI systems, while also making it scalable using off the shelf plumbing parts bought locally.  For the raft side walls, I went with Hardie fiber cement plank 12"W x 12'L. This is very water resistant, and rot/termite proof, so it should be long lasting and it was comparable in price to ACX plywood. ACX plywood would have to be cut into 1ft strips while the Hardie plank is already the correct width. I went with PT 2"x4"x8' for the side rails for durability and weather resistance, with a 1"x 2" furring strip top rails to negate wear on the liner. The assembly process was pretty straightforward and I was able to complete construction of each raft, less the liner installation, in a couple of hours. I measured off an area that was 25ft x 25ft and placed woven weed block down prior to raft construction. I laid this in a cross hatch pattern, double layer which was approximately 1100 sq ft of material and attached it with ground pins. I will be adding edging material later and filling in the area with expanded shale or gravel.

Here are a few pics of the raft construction process, note that I used all galvanized fasteners for construction.

 1"x2"x24" PT stakes were added as side support and to negate any shifting, these were attached with 1/4"x3-1/2" galv. carriage bolts w/nuts and washers.

Since I have two aquaponics systems, I am building two rafts per system for a total of 4 rafts. Each raft is 4'W(actual is 51")x16'L, this provides me with 256sq ft of growing space, with a an average of 30 plants per 1sq meter (10sqft), I should be able to have approx. 768 plants along with those in the grow beds. I also intend to add additional  4'x4' DWC rafts inside the greenhouse. This should up the count to approx. 1000 plants between both system. Of course, once the rafts were finished I had to paint them to match the greenhouse and our home.

Based on my previous design, I am using 2" PVC to connect the beds on the far end using 2" DWV 90deg EL's and 2" non caulking floor drains. The floor drains have an internal rubber busing which can be tightened down on the 2" PVC pipe and if necessary loosened later for removal or expansion.

The floor drains require a 3-1/4 hole saw which is a perfect fit. The only problem I ran into was that the concrete board pretty much destroyed the hole saw after 4 holes...so I will have to buy another one when constructing the second set of rafts..which are kind of pricey at $17 a pop, but hey, it for a good cause, so enough about that. In the pics above I used a scrap piece of board to test the size and fit of the drain...can you say perfect.

Now on to drilling the holes in the raft beds.

 These holes were placed at 5" from the bottom and 25-1/2" on center of the Hardie plank. Remember, I build the rafts 51" wide.

And with that, I end this post as it has now been raining for several days, and I will need to continue this after I have progressed further on my installation of the DWC rafts, hope you find this helpful.

System Expansion Plans

OK...So, I've been toying with the idea of expanding my Aquaponics system to include DWC raft beds. I threw together a little sketch in Google Sketchup to show what it may evolve into later next year. I already have some of the peices needed such as the AquaTop AB120 Blower, Expanded Shale, etc. After careful calculation I can probably throw about $1.5K at it, which would include a Hoop Style Greenhouse covered in 6mil Poly Greenhouse plastic...not bad for the extra I would gain in grow space. I can use the existing system along with the two Danner MagDrive 9.5 -950 GPH pumps that currently sit in the fish tanks along with the Expanded Shale growbeds and the dual 1000W Titanium Aquarium heaters. I can redisign this system into a Constant Height in Fish Tank with no Sump needed. Using an Undercurrent model the Raft beds would be the sump with the pumps sitting outside of the tanks/growbeds while pulling the water through the  DWC raft beds and pumping water backup into the Expanded Shale growbeds. From my calculations even if all of the Shale growbeds filled at the same time/rate, then the rafts water levels would only drop 1.5 inches or 3/4 inch if I installed an indexing valve. The combo Vortex / Swirl filter and degassing chambers along with the shale growbeds should take care of all the filtering for the system. On the Mag pump with a 3' head, I should get about 800GPH out of both pumps , that would circulate all of the water in 4 raft beds in approx. 1hr 19m. The Shale growbeds would flood and drain approx. 3 times per hour.  Taking all growbeds into consideration, initially I will have 345Sq ft of growbed space. Using the assumption that you need .3LBs of fish per square foot of growbed space, I would calculate that 103 +/-  1Lb fish are needed for the system, approximately 25 fish per 175 Gal Tank.  I have the capacity to add another 2 Raft growbeds and up my count to 150 fish total.  Here is a quick fly by of the system.

 

DWC Raft beds are fed by 2" PVC through to the water pumps. Media grow beds use standard 1" PVC drain pipe and 1/2" PVC fill pipe with ball valves for flow control. AquaTop Blower uses 1" and 3/4" PVC pipe with flexible tubing feeding 6" air stones every 3ft in the Raft beds and 12" air stones in each Fish Tank.  I have calculated a need for approx. 6CFM total for the system @ 10" H20, and 2CFM @ 24" H20, which the AquaTop AB120 should provide.

GrowBed content has arrived.

Ok, the only thing left to do is fill the growbeds with media, after researching the various options, I narrowed it down to two choices, either Growerstone or Expanded Shale. Due to price, Growerstone in bulk is $3 per cubic ft plus delivery and Expanded Shale is $2.22 per cubic ft plus delivery. I decided on the Expanded Shale, and ordered 3 cubic yards from a local source which was promptly delivered in an hour at a price of $258.00. It takes approximately 23 cubic ft to each growbed and I have four to fill... and so it begins.

 Due to dust from processing the Expanded Shale, It needs to be washed to remove any residue. I accomplished this by taking a 5 gallon plastic bucket and drilling some 2-1/2" holes in the bottom and the placed some left over wiring screening I had laying around, this not only helps with removing dust/sand from the Shale but also helps in grading the size of the material. I should get a pretty consistent 3/8" stone size on the shale.

I tried using a regular spray hose to clean the shale, but it was not very effective, so I broke out the pressure washer and gave it a spin. I filled the buckets up about 1/2 full with shale and pressure washed it with a fan spray which seems to work fairly well. It does however breakup and create smaller granules which I can't separate out, this will just have to go in the beds, and hopefully it will not cause clogging problems later on.

It takes about 30 minutes to clean a 6CuFt wheelbarrow full of shale and another 10-15 minutes to unload it into the grow beds.

It takes approx. 4-1/2 wheelbarrow to fill a growbed, so it is somewhat time consuming to do so, but hopefully well worth the effort in the long run, and finally the first growbed is complete. The media is 1" to 2" inches above the water fill line. This prevent algae growth on top of the media in the beds.

After filling the growbeds with media, I still have about half of the Expanded Shale left, obviously I received a lot more than 3 cubic yards, so that will go into the raised beds for water retention and aeration which I am planning on putting in before winter sets in.  I planted a few herbs and a couple of tomato plants to see how the plants would do in the growbeds.

I still need to test the water for ammonia, nitrites, nitrates to determine the levels and whether the plants are doing there job in using the nitrates and whether the bacteria have kicked in and are converting the waste into usable Nitrates for the plants. I guess that means I have to buy a test kit...on my list of things to do.

And now it's on to the worm beds.....

Finishing up on the Greenhouse

Well, I have made great progress on the greenhouse, it has been painted up, the roof and window panels are installed, along with a ridge vent.  I have two windows that open for more air flow during those "hot" times, with screening to keep the bugs at bay...it was a chore, but well worth the effort. Here are some pics....

 I still have to place the storm door which was graciously donated by my neighbor "Skip" whom I wish to thank. After which I will be placing the substrate for the flooring which will consist of sand/gravel and paver stones, and due to the excessive heat buildup I will be placing a gable mounted solar powered attic fan in one end of the building with possibly a "Swamp cooler" in the other once I run the electric and water to the building....more to come.