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iAVs/DWC Comparison

Frequent heavy rain stopped work on this system, this week…but sand beds were still the subject of discussion elsewhere in the world.  

Fresh on the heels of the iAVs/DWC comparison study conducted by Hisham El Essawy at the American University in Cairo (AUC), is another study that sought to compare lettuce yields between a DWC and with a “sand-bed system.”   Like its predecessor, the latter study, by Lobna Salem (also from AUC), failed to optimise either of the units thus bringing the study outcomes into question.

While I’m delighted that universities are starting to demonstrate an interest in iAVs (even when they are not aware of it), I regret that we were not associated with the researchers because these comparative studies would have been better served if they’d sought advice about what sand can do…particularly using the iAVs method.  The rainy weather provided an opportunity to take a close look at both theses.

The really interesting thing that has come out of the two AUC studies is the confirmation (yet again) of the versatility of iAVs.  We’ve seen some outrageous deviations from the instructions and guidelines…and yet the iAVs (or other sand-bed aquaponics) still grows plants…and better than any other media bed that I’ve seen.  

New Worm Farm

The new worm farm is now in operation.  I put some coco coir into the bottom to allow the worms somewhere to retreat if conditions weren’t to their short term liking.  I then transferred the worms – and several kilograms of castings.  I topped the bed off with several layers of weathered cardboard smeared with the larvicast out of the BioPod.   I’m planning to use worm castings in the evolving organic hydro units and while, we’ve got modest stocks of vermicast, we’re also experiencing cooler weather.

New Ebb and Flow system

The old worm farm is now the new ‘ebb and flow’ hydroponics system.  The grow bed is a fraction under one square metre in area…holds about 200 litres when full, and is, at the moment,  part-filled with clay pebbles.  Below the grow bed is a 200-litre nutrient tank.  A small submersible pump controlled by a timer…and some simple plastic fittings…facilitate the pumping of water from the nutrient tank up to the grow tank.  An electro-mechanical timer – and a simple standpipe arrangement – ensure that a predetermined amount of water gets pumped up.  Once the pump is shut off, the water drains back into the nutrient reservoir… and awaits the next irrigation event.

Organic Hydro Biofilter/Brewer

It’s been about a week since the ammonia level in this system dropped to zero.  I’m currently waiting for nitrite levels to rise.

Seedlings on Steroids

I’ve left a bunch of pak choi seedlings in the seedling propagator – well past the time that they should have been planted out.  I’m keen to see how they turn out so I’m going to put some of them into 2″ NFT pots – and some others directly into the clay pebbles in the new ebb and flow system.

The Emerging Vision

The overall plan for Havemore Farm is to turn it into a fully-functioning waste transformation micro-farm…showcasing a variety of food production (and other lifestyle development) options.

As recently as a few months ago, most of our food production capability had been mothballed.  

We have considerable capacity once it’s all up and going.  

But it’s all useless if it’s sitting idle. so, sometime back, I decided that, before taking on any new projects, I’d put everything that I had lying around to work growing food.  I decluttered the backyard and unearthed a number of tanks and tubs…and incomplete projects.

That means that there will be new projects happening soon.  They include:

  • IBC Test Bed system
  • Mega Bin duckweed unit
  • Organic Hydro Biofilter/Brewer 2.0
  • Pond Biofilter

More details on the new projects will be available next week.

Got any ideas or suggestions for improvement in this weekly report?  I’d love to hear from you…and it doesn’t matter what it is…I’ll give it a try.  More pictures…less reading?  Bigger pictures?  Prefer video?  More links?

Until then, keep growing – and take it easy.