GaryD

Demo iAVs System

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Goldfish are great but have tryed considering roseyreds since this is smaller system you could have more and maybe price per fish and feeding cost will be more effective.

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Hi SA

No updates?

 

here

 


The iAVs Demo System still has to be commissioned but a rainy weekend has delayed that.....coupled with the fact that I need to move it and that will require  that I unload it.   Clairvoyancy would be a useful skill for those undertaking project sprints.

 

BTW, the rainy weekend didn't mean I got to sit around.  I got to move 40 barrow loads of tree mulch into the Permaculture garden.

 

Gary

 

cheers

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Hi,

 

Moved the unit yesterday.

 

I'm currently running water through the system and it's draining through the sand as fast as it enters the sand bed.  This is to be expected given that the sand is 'brand new' and will change once I start to get some sort of microbial action happening.....and particularly when algae starts to form.

 

I've changed the inlet header so that I can regulate and balance the flow to the sand beds.

 

I'll do some opening water tests today.  The results will be somewhat predictable since i'll be using rainwater but we need a confirmed baseline.

 

I was thinking of using oxidised urine to cycle the system.   I have 200 litres of pee tea brewing so there's no shortage.

 

Any questions - or anything you'd like me to try - at this stage.

 

 

Gary

Edited by Gary Donaldson (see edit history)
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looking forward to learning about the specs of this system!

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Hi Wendy,

  • The fish tank is of about 250 litres.
  • The sand bed/biofilters are 50 litres each - and of about 4 square feet in area.
  • The sand is filter sand that is consistent with the iAVs prescription.
  • The water pump is a submersible pond pump - 1400 litres per hour.
  • An air pump will be used to provide aeration for the fish tank.
  • The flood and drain regime will be controlled by a digital timer.

I'll measure the fish tank and sand beds tomorrow.

 

What else would you like?

 

Gary

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What have you got propping up the sand beds? This is still my big dilemma, how to raise the beds above the fish tank that probably can't be put in the ground (tree roots, concrete).

 

I'll post in my California thread, but maybe I should decrease my fish tank size (making it shorter) so that I don't have to lift the sand beds so high. I'm just partial to being able to grow lots of plants so I was trying to utilize the full size of everything I have…

 

You mentioned to Old Prospector that you figured on one plant per sand bed in this system…  Greedy me, I fear I'll be trying to cram plants in.

 

Also, what kind of containers are they? From an aquaponics supplier or local hardware store?

 

And can we see pictures of inflow/outflow pipes?

 

OH, and is there an article or other resource about using aged urine to cycle the system?

 

Haha, you thought it was so straightforward and simple, right? Some of us are denser than others apparently :)

Edited by neighbor (see edit history)
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Hi Wendy,

  • The fish tank is of about 250 litres.
  • The sand bed/biofilters are 50 litres each - and of about 4 square feet in area.
  • The sand is filter sand that is consistent with the iAVs prescription.
  • The water pump is a submersible pond pump - 1400 litres per hour.
  • An air pump will be used to provide aeration for the fish tank.
  • The flood and drain regime will be controlled by a digital timer.
I'll measure the fish tank and sand beds tomorrow.

What else would you like?

Gary

I would suggest you to relook at your pump..If it works at max efficiency, there won't be any water in your fish tank in less than 10 minutes or so..your filter would overflow..and with that velocity all your sand would move and would be in your fish tank. Edited by vkn (see edit history)

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On my system I have each supply line to the GB's controlled by a ball valve and one ball-valve-controlled line diverted back into the ft to use any excess water pressure to keep the water moving a little so the pump has the chance to pick up any junk that may be passing by while my pump is running at full capacity.  Not intending to diminish your observation, but I would think Gary has his under control as well.  

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Any fish water with wastes diverted back to the fish tank is a poor design in any Aquaponics system..you can't accomplish a balanced system that way..it just help churn the fish wastes within the fish tank resulting in a muddy looking system, lots of stress to the fish, etc..lessons learned. First, one needs to meet thier volumetric ratios and then choose their equipment appropriately. I thought those basic principles are very too simple to understand. Hope it helps..if it doesn't, forget it.

Edited by vkn (see edit history)
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On my system I have each supply line to the GB's controlled by a ball valve and one ball-valve-controlled line diverted back into the ft to use any excess water pressure to keep the water moving a little so the pump has the chance to pick up any junk that may be passing by while my pump is running at full capacity.

 

How many tank exchanges per 8 hrs, do you get doing it this way?

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What have you got propping up the sand beds? This is still my big dilemma, how to raise the beds above the fish tank that probably can't be put in the ground (tree roots, concrete).

 

I'll post in my California thread, but maybe I should decrease my fish tank size (making it shorter) so that I don't have to lift the sand beds so high. I'm just partial to being able to grow lots of plants so I was trying to utilize the full size of everything I have…

 

You mentioned to Old Prospector that you figured on one plant per sand bed in this system…  Greedy me, I fear I'll be trying to cram plants in.

 

Also, what kind of containers are they? From an aquaponics supplier or local hardware store?

 

And can we see pictures of inflow/outflow pipes?

 

OH, and is there an article or other resource about using aged urine to cycle the system?

 

Haha, you thought it was so straightforward and simple, right? Some of us are denser than others apparently :)

 

The sand beds are supported on cement blocks and treated pine sleepers.

 

When I've completed the video, you'll have the complete picture ('scuse the pun).  That should happen soon and, if it doesn't, I'll post photos.

 

With a total area of just four square feet.....and taking account of furrows....I really only have space for one plant in each bed......unless I grow radishes or some other tiny plant.  I have also thought of using the system as a seedling propagation unit.....producing seedlings for our other gardens.

 

I would suggest you to relook at your pump..If it works at max efficiency, there won't be any water in your fish tank in less than 10 minutes or so..your filter would overflow..and with that velocity all your sand would move and would be in your fish tank.

 

The pump that is currently on the system is the smallest one I had.  You are correct in that it will provide greater flow than I need so I have two options available to me.......I can bypass the surplus water inside the fish tank.....or I can throttle the flow at the control valves on the sand beds. 

 

Bypassing the flow is no issue at this stage since the system has no fish in it.  If I retain this pump, I will probably just throttle the flow.  This is less of an issue that it seems because these small pond pumps are of very simple construction and can accommodate such restriction - and they actually get cheaper to run (counter intuitively) when throttled.

 

As pumps get smaller the outlets become smaller, too.....and become more liable to clogging.  The plumbing that I've used on the system is 19mm (3/4") micro-irrigation stuff.  Anyway I haven't made my mind up about that, at this stage.  I may go for a smaller 1/2" pump and blow through the pipework at regular intervals.

 

The duration of the irrigation cycle is not an issue.  It certainly won't be ten minutes in a tiny unit like this one.  The purpose of the flood cycle is not to run for a particular amount of time but rather to flood the sand bed to saturation.  Once the detritus layer and algae becomes established in the furrows, I anticipate that the flood cycle will be measured in seconds rather than minutes.

 

On my system I have each supply line to the GB's controlled by a ball valve and one ball-valve-controlled line diverted back into the ft to use any excess water pressure to keep the water moving a little so the pump has the chance to pick up any junk that may be passing by while my pump is running at full capacity.  Not intending to diminish your observation, but I would think Gary has his under control as well.  

 

Aufin.....your suggestion that having a bypass will assist the collection of the solids appears, at first glance, a sound idea....but maceration of the solids with the pump makes them more difficult to capture, will negatively impact water quality and can irritate the fish eyes and gills.  VKN is correct in his assertion that bypassing within the fish tank (in a system containing fish) is not good practice.

 

By way of a general observation,  a tiny system like this presents its own challenges and will require some adaptation.  From recollection, this the 13th system that I've built so I'm confident that it can be made to function in a practical sense.  I'm more interested in whether it can produce something useful in they way of food.

 

Many people start off in aquaponics by building a small 'demonstration of concept' system......usually to satisfy themselves (or a partner) that it will work - before they invest in something larger.  Many of those systems produce nothing more than a lettuce or two and generally fail due to water quality issues.....and their builders wander off to try their hand at something else.

 

For such people, something a bit larger (like an IBC) and more resilient would actually have been better.

 

I could have built a much more elegant system - but one of the things that I want to demonstrate is that, using off-the-shelf components, I can easily put together a small unit that will produce real food (not some half-starved lettuce or snow peas) - while demonstrating the core principles of iAVs.

 

Gary

Edited by Gary Donaldson (see edit history)
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Hi Gary,

 

Just out of interest...Where did you get your sand from?...Was it from a local sand depot, or somewhere else?

 

Cheers.

Edited by bigdaddy (see edit history)

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Hi Gary,

 

Just out of interest...Where did you get your sand from?...Was it from a local sand depot, or somewhere else?

 

Cheers.

 

Hi BD,

 

I bought the sand for this project from a specialist sand supplier called Riversands P/L at Carbrook.

 

Gary

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Hi,

 

I've posted a video on the iAVs Demo System - Part 1.

 

Part 1 deals with the reasons that I built the system and with the build itself.   I'm working on Part 2 which is about the start up and operation of the system.

 

Feel free to point out any errors or omissions.  Spielberg is not going to be out of a job anytime soon.

 

Gary

 

 

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That's a great video! Clear and concise and gives a true sense of the simplicity of the system (as you've been saying all along :) ).

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Thanks Wendy......I'm hoping I can build on that with the passage of time.

 

Now for some water tests.....

 

I had a brief bout of anxiety when I tested the water in the Demo Unit.  It read 7.5.  Just as I was formulating the expletives that I would direct the way of the sand supplier, I remembered that I had flushed the system with tap water (rather than use the rainwater) to get rid of some discolouration due to sand dust.   I quietly made my peace with the sand supplier - just to offset the karmic lightning bolt that was coming my way - and started to drain the system in readiness for a fresh batch of rainwater.  All's good.

  • Rainwater - pH 6.5 
  • Tap water - pH 7.5
  • Pee Tea - pH 6.0 - Ammonia 1.0 - Nitrites - 0.25 - 0.5 - Nitrates 40 - 80.  

The rainwater pH is consistent with this area.  The tap water reading is irrelevant because I won't be using tap water but it's there to remind me that jumping to conclusions is unhelpful.

 

The pee tea readings confirm my earlier belief that the tea will be a useful way to cycle the demo system while I'm waiting for fish to arrive.  As the photo suggests, there's a bit of everything there which is consistent with the fact that I only added the most recent 'contribution' about four days ago.

 

As soon as the tank has refilled, I'll decant some pee tea and commence the acclimation (cycling) process. 

 

Gary

post-2-0-37286500-1463535830_thumb.jpg

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Hi Gary,

 

Just backing the bus up a bit and I can't resist asking this much longer :)

 

In your first pics you show the grow beds with the furrows...At the end of the furrows I see some blue plastic things...Are they Ag pipe drains and bends there? and ....If they are, is it slotted ag pipe and why is it there?...Sorry to back up but you've got my curiosity happening now I've obvoiusly missed a lot along the way....

 

Cheers

Edited by bigdaddy (see edit history)

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Hi Gary,

 

Just backing the bus up a bit and I can't resist asking this much longer :)

 

In your first pics you show the grow beds with the furrows...At the end of the furrows I see some blue plastic things...Are they Ag pipe drains and bends there? and ....If they are, is it slotted ag pipe and why is it there?...Sorry to back up but you've got my curiosity happening now I've obvoiusly missed a lot along the way....

 

Cheers

 

No BD.....they're bits of shadecloth poking through the sand.  When I moved the system, I changed that arrangement.....and used a pad of folded of shadecloth as you see in the video that I've posted.  I just knew that the first time I pulled a plant out of the bed that it would take the shadecloth out with it.....plus the new arrangement is a bit tidier.

 

Here's the video.....so I can test my newly acquired YouTube insertion skills......

 

 

Hot damn, Ande.....you're a lengend.

 

Gary

Edited by Gary Donaldson (see edit history)
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Hi,

 

Today, after I conducted a battery of water tests, I drained the system and refilled it with rainwater.....and added 25 litres of high octane pee tea - to innoculate the system with some of the bacteria it will need in advance of the fish arriving.  Getting some bacteria happening will help to stabilise the furrows....and the presence of nitrates will probably trigger an algae bloom.....also good for the furrows.

 

I also hooked up an air pump and two simple airlifts to provide aeration.

 

Gary

Edited by Gary Donaldson (see edit history)
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Hi,

 

I'm continuing to tweak the system in advance of the arrival of the fish next week.

 

I've changed the inflow header - adding two more control valves - to offset the erosion that was occurring with the original set up.  The furrows are now holding their shape much better.  Of course, this will be much less of an issue once we have fish and the detritus layer begins to form in the furrow.  That, and the deposition of algae in the furrow will underpin the shape of the furrows.

 

Gary

post-2-0-67389700-1463886027_thumb.jpg

post-2-0-22671100-1463886061_thumb.jpg

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