GaryD

Demo iAVs System

88 posts in this topic

So... what does freeboard mean? I keep seeing it used, haven't totally figured it out from context...

Actually the way it is used here is slang. The original meaning from boats is the measurement from the top of the boats side to the water line on the outside. So those boards were free of water and are even to this day painted a different color.  So using it as slang got to mean any water to the top was free board. An area free of water yet there to stop you from sinking. In this case just the opposite;  to stop it from spilling out and over. It is an old boat building word. Now slanged for a lot of other terms.  In the ocean a low free board would get you swamped.  A low freeboard or no free space between the media and the lip will swamp your floor.  It is just used here as slang.  Some slang gets into the dictionary and some does not.

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Actually, that is the term used throughout the aquaculture industry.....and elsewhere.  And it means exactly the same thing....the height of the water relative to the top of the thing that is either keeping the water out (the hull) or keeping it in (the tank) with only the context being different.  Wikipedia provides this alternative definition for civil engineering...as does WordReference.com.....

 

2. Civil engineering. the height of the watertight portion of a building or other construction above a given level of water in a river, lake, etc.

 

 I'd say that a fish tank qualifies as a 'construction' for the purposes of this discussion.

 

Merriam-Webster Dictionary feel similarly....

 

:  the height above the recorded high-water mark of a structure (as a dam) associated with the water

 

Then there's the Department of Homeland Security's FEMA site who have this to say about freeboard....

 

Freeboard is a factor of safety usually expressed in feet above a flood level for purposes of floodplain management. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed. Freeboard is not required by NFIP standards, but communities are encouraged to adopt at least a one-foot freeboard to account for the one-foot rise built into the concept of designating a floodway and the encroachment requirements where floodways have not been designated. Freeboard results in significantly lower flood insurance rates due to lower flood risk.

 

Followed by Wiktionary.....

 

2.  The distance between a water level and the top of something that contains or restrains it (such as a dam)......or a tank. (italics mine).

3.  The distance between the top of sea ice and the water level.

 

The term is even used in connection with a particular type of skateboard.

 

The important thing to understand is that, in an aquaculture context, it means the distance from the surface of the water to the top of the tank......and it's important because, if you don't have enough of it, the fish jump out of the tank.

 

Gary

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and it's important because, if you don't have enough of it, the fish jump out of the tank.

 

Gary

 

So what is enough "Freeboard" to keep them from  jumping out of the tank?

 

I use a 1" Freeboard in my tanks so that I have the max amount of water to use, but I also have a folding screen top to keep the fish in.

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It's species-dependent to some extent......but it becomes irrelevant if you cover your tanks......and I suggest all tanks be covered in the interests of child and pet safety.....and predator prevention.

 

Outside of the fish jumping out, the only other real issue comes from the fish tank backing up when the pumping rate overtakes the drain rate.  This is usually due to pipe friction on the drainage side.  It also happens as the filters in the system begin to load up.

 

It's evident when it occurs...by the fact that the system will continue to drain after the pump is switched off.

 

In that event having some freeboard is handy.  The precise amount will depend on the water dynamics within the particular system. 

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Outside of the fish jumping out, the only other real issue comes from the fish tank backing up when the pumping rate overtakes the drain rate.  This is usually due to pipe friction on the drainage side.  It also happens as the filters in the system begin to load up.

 

It's evident when it occurs...by the fact that the system will continue to drain after the pump is switched off.

 

In that event having some freeboard is handy.  The precise amount will depend on the water dynamics within the particular system. 

How would the FT backup? , if you start with a known volume of water, and start the pump and for example you pump 25% of the volume to the SB, the only way to backup the FT is that you drain back more than what you pumped.

 

​But the SB can backup, for the reasons given.

 

​The only evidence to this scenario is that you need to lower the pump timer.

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This thread is a good example of where things can go awry.

 

The discussion about freeboard started off with a question from Old Prospector about the amount of freeboard in a sand bed.  I responded and that prompted a question from Neighbor.  That produced a cryptic comment from Mark and a relatively useless post from Deuem.....and that prompted a similarly useless response from me.  Now, Mark was sharing another unwanted view about the human condition....Deuem was showing us that he knows the tautological origins of the word 'freeboard'.......and I was just digging another hole to throw myself into.

 

Since Neighbor got the answer she needed from Old Prospector.....that should have been the end of it.  Instead, we wasted time venturing into another dry gully.

 

Meanwhile, Old Prospectors most recent post reminds us that we were supposed to be talking about the freeboard on the sand beds (where my feeble mind had been diverted someplace else).....which led me to talk about freeboard from a fish tank perspective.....actually the microFish Farm tank to be specific.

 

After all of that, we are hopefully all back at the freeboard in the sand beds.

 

How would the FT backup? , if you start with a known volume of water, and start the pump and for example you pump 25% of the volume to the SB, the only way to backup the FT is that you drain back more than what you pumped.

 

​But the SB can backup, for the reasons given.

 

​The only evidence to this scenario is that you need to lower the pump timer.

 

In the context of the Demo Unit, there is no back up in the fish tank......and I apologise for my part in the confusion.

Edited by Gary Donaldson (see edit history)

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Hi,

 

In an attempt to prevent this thread from being hijacked by the continuing BS over freeboards, I've concealed several posts and I will continue to do so until we bring the troll activity under control.

 

Gary

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The purpose of a demo unit is to prove a concept before committing to a full scale working project,We need to know if this gives better results than what we already have. The temperatures in various parts of the world are interesting as are nautical terms but nothing to do with this thread.

 

Lets find out if it grows Plants? and does it do so efficiently . :devil:

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Hi Mike.......good to hear from you again.  What's happening in your world?

 

Gary

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Sorry for leading you astray.  I'll assume that you're doing well....unless you PM me to the contrary.  

 

Got anything that you'd like to share about 'freeboard'?  I'll grant you a late pass just so you don't have to the only person in the world to miss the opportunity to venture an opinion. 'wink'

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A few days ago, I planted some silver beet (Swiss chard) in one tub and some broad (fava) beans in the other.

 

For the past couple of days, we've been getting steady rain......good in one sense....but it's diluting the nutrients that I brough across from the microFish Farm.  I may have to look at a storm cover for the little thing. 

 

Any new pictures of the demo?

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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

 

I've changed the inflow header - adding two more control valves - to offset the erosion that was occurring with the original set up.

 

That seems strange to me, since Dr. Mark, already had that problem solved with the header supply inside another larger pipe with holes.

 

Why didn't you do it his way?

 

You even stated that way in the iAVs website tutorial.

 

If you'd followed the original design you would save the costs of 2 ball valves.

 

We've tried this design of water distribution of Dr. Mark's and surprising enough it a well designed. Thanks to you Dr. Mark.

 

 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.

 

​Also in the iAVs website tutorial, it shows the furrows cross connected to one another at the ends, for a more even distribution.

 

Why did you vary from Dr. Mark's design?

 

We've also have tried his design of cross connecting of furrows, and "Murphy's Law" shows even tho water flows across sand in different furrows, some will run faster than others, but with cross connecting furrows that gives better control.

Edited by Old Prospector (see edit history)

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A few days ago, I planted some silver beet (Swiss chard) in one tub and some broad (fava) beans in the other.

 

For the past couple of days, we've been getting steady rain......good in one sense....but it's diluting the nutrients that I brough across from the microFish Farm.  I may have to look at a storm cover for the little thing. 

 

 

Gary,

 

I understand that all We frequently get bouts of jungle rain here, especially in the afternoon due to atmospheric heating.  They'll generate short, but torrential downpours in the summer. Every square meter of grow bed is a great rainwater catcher, isn't it?  It will drain back into the reservoir, or fish tank, and do numbers on nutrient density, PH and other water parameters.  

 

Speaking of which, over the last 15 minutes a squall line is starting to pass over my house.  It's 1:40PM here and it looks like dusk.

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Gary,

 

I understand that all We frequently get bouts of jungle rain here, especially in the afternoon due to atmospheric heating.  They'll generate short, but torrential downpours in the summer. Every square meter of grow bed is a great rainwater catcher, isn't it?  It will drain back into the reservoir, or fish tank, and do numbers on nutrient density, PH and other water parameters.  

 

Speaking of which, over the last 15 minutes a squall line is starting to pass over my house.  It's 1:40PM here and it looks like dusk.

 

Hi Craig,

 

If you look at VKN's thread, you'll see that he uses rain shelters......with plastic (I think) roofs and shadecloth sides.  You're right, if you allow rain to flood your systems, you will alter your test readings.  Having said that, I've often used a weather event to flush my systems.

 

Unless you live in a place with 'ideal' weather, consistent food production requires some environmental control.

 

Gary

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The rains also beat down the hills for the plants.  I recommend cover.

 

Hi Aufin,

 

I hadn't even considered the rain destroying the furrows.  Makes sense.

 

Gary

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Hi Aufin,

 

I hadn't even considered the rain destroying the furrows.  Makes sense.

 

Gary

Unless one lives in a region where it hardly ever rains.  So that when it does, one's sole concern/interest is in collecting as much water as it as possible for use throughout the remainder of the year.  In which case you more likely to benefit from shade structures (single or multiple 'levels') and/or protection from wind damage/abrasion.  Once one has collected sufficient water to grow through the remainder of the year (or any significant portion thereof), then re-establishing some  furrows should require but an hour or so.  What one does in a particular environment is entirely dictated by local factors. IMO.

Edited by Mark McMurtry (see edit history)

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Hi

split/cut/moved Old Prospector's post as it was of topic in original thread

Gary

Do you have any updates on your Demo IAVS system?

How is the build of the "Parking Space  IAVS system"  going?

 

cheers

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Hi Terry,

The Demo iAVs is still sitting just outside my workshop door but it's turned off for the time being.  I anticipate getting it going in the coming day....initially to propagate seedlings.

The "parking space iAVs system" is still making its way to the top of the project list.

iAVs had dominated my time for the past couple of years...to the point where many other things had taken a back seat.  So, I decided to adjust my priorities so that everything got its share.

Gary

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On 10/28/2016 at 7:57 AM, GaryD said:

The Demo iAVs is still sitting just outside my workshop door but it's turned off for the time being.

iAVs had dominated my time for the past couple of years.

Thanks for documenting your IAVS project.

Just wondering if you had a problem with this system that stopped it growing plants and fish ?

It would be really helpful to know of the possible pitfalls because I am thinking of doing a similar system.

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Hi John46,

I built this system with a view to demonstrating iAVs - on a very small footprint.

Other priorities got in the way, for a few weeks, so I just fiddled with it.  

I had some small fish in it for a few days - but they had non-iAVs issues and died.

In fact, after the fish died, I switched the system off and it just sat there.

A week ago, I turned it back on....and I find that the sound of running water (a life-giving sound) encourages me to think.

My observations:

  • Technically, It can only be an iAVs as long as it has fish in it.
  • This system....with fish in it....is a biological process....complete with soil microbiology.
  • Without fish....it's hydroponics....and the plants will be fed inorganic chemicals....in their most cost-effective plant-available form.  One such very well-known combination is Hoagland's solution...it's chemistry. 
  • A small system, like the Demo System can be used to demonstrate all manner of useful things.
  • In small systems, things change...things change....for better or worse...quickly!  Critical success factors like water temperature and water quality  can change and put the fish at risk....and even topple the system.
  • I won't put fish back into a system of this size without being able to completely control the environment in terms of water temperature and quality.  That's not hard; it just takes time....and that means that it will be prioritised.
  • I use a lot of plants.  We obtain them from all manner of places.....some cost money and others are free.
  • I'd like to know a lot more about how seed germination works in a sand bed.
  • Seed germination requires little or nothing in the way of nutrients...depending on the stage at which they'll be transplanted.

Given that I have the system hardware....some seeds....warm weather.....there's nothing standing in the way of me doing that...right now!

To summarise...the Demo iAVs system is...NOT!  What we have here (currently) is a sand bed, a nutrient tank a pump and some very basic plumbing...and some nutrients of a known provenence and formulation.  We will be adding a very dilute nutrient solution given that our goal is to sprout the seeds and then grow them through to the optimum size for transplanting.

Once I learn more about seed germination, I'll try something else.  If, in meantime, I've managed to create a CEA chamber to protect the various organisms in the system....including fish (in most forseeable situations)....I'll swing it across to iAVs.

John, there was probably a quick and easy way to respond to your question....but I was overdue for a progress report on the Demo System...so I get to kill two birds with the one stone.

'Scuse the loud thinking.

Gary

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Thanks for the update Gary, much appreciated.

I can see that a mini system could be finicky.

Do you think a small IAVS system may need constant aeration for the fish, considering the irregular nature of the water pumping ?

Maybe the water got too hot causing a drop in dissolved oxygen.

I imagine a small plastic tank would be prone to overheating, especially if the sun hit it.

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3 hours ago, GaryD said:

Hi John46,

I built this system with a view to demonstrating iAVs - on a very small footprint.

Other priorities got in the way, for a few weeks, so I just fiddled with it.  

I had some small fish in it for a few days - but they had non-iAVs issues and died.

In fact, after the fish died, I switched the system off and it just sat there.

A week ago, I turned it back on....and I find that the sound of running water (a life-giving sound) encourages me to think.

My observations:

  • Technically, It can only be an iAVs as long as it has fish in it.
  • This system....with fish in it....is a biological process....complete with soil microbiology.
  • Without fish....it's hydroponics....and the plants will be fed inorganic chemicals....in their most cost-effective plant-available form.  One such very well-known combination is Hoagland's solution...it's chemistry. 
  • A small system, like the Demo System can be used to demonstrate all manner of useful things.
  • In small systems, things change...things change....for better or worse...quickly!  Critical success factors like water temperature and water quality  can change and put the fish at risk....and even topple the system.
  • I won't put fish back into a system of this size without being able to completely control the environment in terms of water temperature and quality.  That's not hard; it just takes time....and that means that it will be prioritised.
  • I use a lot of plants.  We obtain them from all manner of places.....some cost money and others are free.
  • I'd like to know a lot more about how seed germination works in a sand bed.
  • Seed germination requires little or nothing in the way of nutrients...depending on the stage at which they'll be transplanted.

Given that I have the system hardware....some seeds....warm weather.....there's nothing standing in the way of me doing that...right now!

To summarise...the Demo iAVs system is...NOT!  What we have here (currently) is a sand bed, a nutrient tank a pump and some very basic plumbing...and some nutrients of a known provenence and formulation.  We will be adding a very dilute nutrient solution given that our goal is to sprout the seeds and then grow them through to the optimum size for transplanting.

Once I learn more about seed germination, I'll try something else.  If, in meantime, I've managed to create a CEA chamber to protect the various organisms in the system....including fish (in most forseeable situations)....I'll swing it across to iAVs.

John, there was probably a quick and easy way to respond to your question....but I was overdue for a progress report on the Demo System...so I get to kill two birds with the one stone.

'Scuse the loud thinking.

Gary

Hello from the Aloha State. When I was a teen one of my jobs was working at a nursery. One of my tasks was taking seedlings and transplanting them into greenhouse sand beds. After they grew a little they were potted and put outside. The sandbeds had sand and perlite. That is all.  Anyway, I thought this was similar to what you were doing....  Maybe plant seedlings, wait, then add fish....? Any reason perlite cannot be added to tbe first 8"?

Edited by Strider (see edit history)
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