Announcement

Collapse
No announcement yet.

Gary's first Sandponics System

Collapse
This is a sticky topic.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    I've reached the point where I've now got a sand biofilter and a sump tank and the water has been recirculating between the two for the past few days. I have yet to order a pump and fish for the system...so I'll be engaging in some simple tests of the sand in the meantime.

    A quick word about the sand...again!

    Consistent with the iAVs prescriptions, the sand must be inert...and being that the sand is made from recycled glass there can be no doubt about that.

    The sand must drain effectively. If anything the glass is probably on the coarse side of the iAVs prescription. The upside of this is that drainage will be good. The downside is that inflowing water will sink into the sand rather than run along the full length of the furrow...until the detritus layer and algae begins to form.

    The sand should be free of any silt or clay. There's a slight turbidity in the water but it's more likely to be dust...most of which will disappear with the first cleaning of the sump tank.

    Recirculating the water through the sand, in recent days, has flushed some pale sediment that I've confirmed to be powdered glass. A few grains of sand have drained into the tank. They feel like very small grains so I'm guess that this is some undersized material that flushing through. In both cases, I'll recover this sediment and dispose of it while it's still wet - into the compost heap.

    Click image for larger version

Name:	DSCN8582.jpg
Views:	96
Size:	167.1 KB
ID:	2769

    Comment


    • #17
      will sink into the sand rather than run along the full length of the furrow...until the detritus layer and algae begins to form.
      In my little iAVS inspired system, the detritus layer actually vanished again after a while causing the water to sink again. In the early stages, this shouldn't be too much of a hassle, but in my mind, the system will not benefit from the whole biofilter if it does not flood. I am keen to see what happens in your system.

      Comment


      • #18
        Consistent with the iAVs prescription, I have shaped furrows...three of them. This sand bed is 1.2 metres (4') wide.

        Click image for larger version

Name:	DSCN8585.jpg
Views:	97
Size:	167.9 KB
ID:	2773

        Because my sand is slightly coarser than the iAVs prescription...and so that I can plant the entire bed out...I've fabricated a watering grid - with 6mm (1/4") holes - at 150mm (6") centres.

        Click image for larger version

Name:	DSCN8587.jpg
Views:	73
Size:	168.7 KB
ID:	2774

        The watering grid will ensure that water enters the furrows along their entire length...and that water is available to every plant.

        Click image for larger version

Name:	DSCN8588.jpg
Views:	74
Size:	190.3 KB
ID:	2775

        There's another reason for the watering grid...and I'll cover that in my next post.

        Comment


        • #19
          A year or so ago I tried something along the same lines as your grid system, but with the pipes laying on the sand with the holes pointing up. Looks to me like you're going to be drilling holes in your "sand" instead of allowing for a gentle flow carrying solids to be filtered/deposited on the surface of your furrows. Also, didnt take too long and I was chasing around with a small stick unclogging plugged up holes. Also, didnt notice a valve to control the water flow/force.
          . Of course, your "other reasons" for building your grid may make my observation moot. Carry on, Gary. Bout f'n time you got your very own iAVs under way. Anxious to see the results.

          Comment


          • #20
            Hi Gary,

            If we could back the bus back a bit, please? The sumps you installed. What size are they in comparison to your grow beds?

            Cheers.

            Comment


            • #21
              At this point, my proposed iAVs...with a sand biofilter and a sump tank (aka nutrient reservoir)...is actually a simple hydroponic system.

              Sand culture hydroponics was one of the earliest soil-less growing methods...and it's still used today in various configurations.

              I'm still not quite ready to start my system up with fish...so I'm going to try growing some plants in the sand bed...hydroponically...using a 2-part inorganic nutrient mix.

              And that brings me to the matter of the watering grid...

              The plants...Asian greens called bok choi are fast-growing...and, based on past experience, they'll probably be ready to harvest in about 20 days.

              I'm anticipating some transplant shock since these seedlings were grown in a pottery mix which I washed clear of the roots. I could have planted the seedlings as they were but I wanted to avoid introducing the potting mix into the clean sand.

              When I started to recirculate the water, a few days ago, I set a timer up to provide me with 8 irrigation events...each at two-hourly intervals...with a run time of 15 minutes. The bed drains for 105 minutes between each flood event...and, consistent with the iAVs specification, it continues to drain overnight.

              The sand is draining so freely, at this point, that I've decided to adjust the watering regime to 15 minutes ON - 105 minutes OFF...24/7...just to ensure that that the seedlings don't dry out.

              Comment


              • #22
                In deference to iAVs - and its inventor - I've changed the title of this thread to "Gary's First Sandponics System"...particularly since. along the journey to my first iAVs, I'll take the opportunity to do some non-iAVs deviations...into things like inorganic - and organic - hydroponics...and some other stuff.

                My first goal is to produce clean fresh food. While iAVs is the best food production system that I've encountered...it's not necessarily the best way for every plant...in every situation. That begs the question of how effectively it can be integrated into other growing systems...for specific crops like leafy greens, baby greens and micro-greens...using nutrient film technique (NFT) and/or deep water cycle (raft - DWC).

                From purely a logical commercial standpoint, the idea has merit and is worthy of testing.

                What I'd like to do is take this opportunity to get a sense of what each of my growing systems...Sand (glass), clay pebbles, NFT, DWC...will do with a 2-part inorganic chemical nutrient mix...and then how the combination will perform as a hybrid iAVs. Then I'd like to test glass sand against quartz silica sand to establish whether there are discernible differences.

                Comment


                • #23
                  Originally posted by bigdaddy View Post
                  Hi Gary,

                  If we could back the bus back a bit, please? The sumps you installed. What size are they in comparison to your grow beds?

                  Cheers.
                  The sump tanks have a capacity of 200 litres each.

                  Comment


                  • #24
                    Originally posted by Aufin View Post
                    A year or so ago I tried something along the same lines as your grid system, but with the pipes laying on the sand with the holes pointing up. Looks to me like you're going to be drilling holes in your "sand" instead of allowing for a gentle flow carrying solids to be filtered/deposited on the surface of your furrows. Also, didnt take too long and I was chasing around with a small stick unclogging plugged up holes. Also, didnt notice a valve to control the water flow/force.
                    . Of course, your "other reasons" for building your grid may make my observation moot. Carry on, Gary. Bout f'n time you got your very own iAVs under way. Anxious to see the results.
                    I'm under no illusions about the maintenance involved in the use of watering grids. I used them when I built my first backyard-scale system about 13 years ago. They'll only be used for the hydroponics stage of the project...since I don't expect a detritus layer to form until I start to use fish in the system. Mind you, algae might develop in the interim. We'll see.

                    I've just planted out the sand bed and, even with the watering grid in place, the seedlings at the far end of the bed don't appear to be getting water. Once the Sandponics system is operating as it should, the need for the watering grid will lapse.

                    Comment


                    • #25
                      OK...picture time.

                      The sand bed has been planted out with silverbeet (Swiss chard) and bok choi...an Asian green.

                      Notwithstanding the watering grid, the water is not reaching the end of the bed...and the glass sand appears dry...so it will be interesting to see if the seedlings that part of the bed are able to access water before they expire.

                      Click image for larger version

Name:	DSCN8599.jpg
Views:	78
Size:	216.9 KB
ID:	2818

                      The DWC tank in the background is full of water - but since I have yet to make the 'rafts' I've put some duckweed in the tank.

                      This is the simple weir arrangement that I use to set the water level in the tank while ensuring that the duckweed doesn't disappear down the drain.

                      Click image for larger version

Name:	DSCN8598.jpg
Views:	48
Size:	181.7 KB
ID:	2819

                      My small NFT system is the third system coupled up to the same sump tank (and nutrient reservoir)

                      Click image for larger version

Name:	DSCN8601.jpeg
Views:	49
Size:	117.1 KB
ID:	2820

                      While the pipework for these systems looks like a cat's breakfast, it's only temporary - and nothing's glued up yet. In the not-too-distant future, it will all change again as we switch over from our current dabble with inorganic hydroponics to iAVs.

                      Click image for larger version

Name:	DSCN8602.jpeg
Views:	49
Size:	152.1 KB
ID:	2821

                      Of general note, the glass sand is draining well...so well, in fact, that I can run the inflow to the bed full-time without the furrows (or the bed) overfilling.

                      Click image for larger version

Name:	DSCN8606.jpg
Views:	51
Size:	192.0 KB
ID:	2822

                      Comment


                      • #26
                        The iAVs Facebook group contains a series of posts about how to prevent deformation of the furrows...some of them interesting.

                        My latest addition to the cluster of systems that I have coupled up on the same nutrient reservoir is this small ebb and flow system.

                        Click image for larger version

Name:	DSCN8609.jpg
Views:	66
Size:	60.8 KB
ID:	2828

                        The plants are some bedraggled kangkong (water spinach) plants that have been clinging tenuously to life.

                        Comment

                        Working...
                        X