GaryD

Demo iAVs System

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So how high is the freeboard along the sides?

 

Hi Terry,

 

I'm guessing that, by the time the furrows become more clearly defined, the freeboard may be something like 2.5 - 3 inches.

 

Gary

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

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neighbor, on 22 May 2016 - 10:35 AM, said:

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

 

the measurement from the top of the sand to the top of the container.

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Hi

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

 

cut/paste from here  http://www.fema.gov/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.

 

 

cheers

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Yep, but my dictionary (old fashioned, paper etc) gives 3 definitions, none of which made sense relative to sand in a container (as opposed to ships or undercarriages of automobiles. Maybe the 2nd def, related to flooding as ande's offering does, seems closely related to some folks but it didn't to me). I figured, if I wanted to know how it related to iAVs, I should ask the folks who might know.

 

Old Prospector was able (and willing) to offer a concise and contextual explanation. Much obliged.

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Hi Gary

 

When you say filter sand is that the same sand that is sold for use in pool filters?  

 

I have access to filter sand that has been removed when servicing pool filters, though am concerned what other things may have accumulated in it.  Not sure what chemicals may typically be used in pool systems (other than chlorine).

 

I also have access to old zeolite from pool filters. I'm guessing that might not be so good for growing in as it may hold onto nutrients too well. Any thoughts?  I realise its not 'ideal' though just looking at cheap available resources I have close by.

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Yep, but my dictionary (old fashioned, paper etc) gives 3 definitions, none of which made sense relative to sand in a container (as opposed to ships or undercarriages of automobiles. Maybe the 2nd def, related to flooding as ande's offering does, seems closely related to some folks but it didn't to me). I figured, if I wanted to know how it related to iAVs, I should ask the folks who might know.

 

Old Prospector was able (and willing) to offer a concise and contextual explanation. Much obliged.

Wendy,

1. If you have a question, ask.

2. OP's response was accurate

3. My snark was directed at Ande's complication - which may apply in Norway

4. In the link I included def. 1 c) 'works' best for me.

5. basically, its a measurement of where water level is acceptable and where it would become a serious problem.

What elevation are people 'assuming' as "the top of the sand"? I'm guessing many have different definitions of this also.

Not that this matters (except on a forum). Point being, keep the water where you want it = keep it away from where you don't.

Edited by Mark McMurtry (see edit history)
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Thanks for starting your demo gary and the youtube documentation helps visually recognize the simplicity of your design. 

 

 

You said you may be using goldfish but maybe i missed it .. is that what you firmly decided on?

 

From my understanding iAVs was designed and tested with tilapia. And while tilapia are legal in many parts of the US they are only really a year round outdoor option in the most southern tips of a few states. Are there other US fish that have been tested with iAVs. What criteria would i be looking for if trying to do a test system with US native fish?

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Hi Brian,

 

I thought that I might have to use goldfish when it appeared that I might not be able to get food fish.

 

I was wrong about that and, just today, I took delivery of 100 jade perch......about 60mm in length.

 

They're an Australian native tropical (warmwater) species.

 

The connection between tilapia and iAVs is an important one.  Mark chose them because of their robustness and he's made it clear that iAVs "was never about the fish" - it was always principally horticulture.  The fish were always a means to an end.

 

Your question is a good one.....and one that needs to be researched more thoroughly.  Even my use of jade perch won't provide the definitive answer because, while they are not as tough as tilapia (nothing much is), they can handle variable water conditions and they grow quickly.

 

I've given this considerable thought, and while nothing will replace practical testing, it seems logical that other species will be able to be used.  I say this because fish like barramundi, trout and other species that require clean water have all been grown successfully by some people in (dare I say it) the basic flood and drain system......and with even greater safety in flood and drain systems with dedicated mechanical and biological filtration.

 

This is where logic kicks in.  

 

Given the fact that other species have been used with other aquaponics variants, there's no reason why other species should not work with iAVs.

 

I have no reservations from a filtration perspective.  Sand is already better than anything else in popular use.  

 

My only concern would be for dissolved oxygen....and mainly for overnight when the water pump doesn't operate. 

 

I would advise that the fish tanks be aerated - 24/7 - and, for the added safety margin, I'd do it even with tilapia.

 

Incidentally, there's scope to vary the irrigation cycle frequency and duration if water quality was shown to be an issue.  It might also be necessary to vary some paramenters for light feeders or slow growing fish....just to ensure that the plants get what they need out of the deal.

 

Gary

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How big was your fish tank again? 200L and 100 jade perch? Hmmm.... What's your plan as they grow?

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Hi Mathias,

 

The 100 jade perch are in the microFish Farm Lite that I built in recent days.  In fact, they're the reason that I assembled it again......so that I would have fish for my various iAVs projects as they unfolded.

 

i'll put a very small number in this system and work it so that, as they grow, I'll remove them one at a time to maintain a standing biomass.....just enough to provide some nutrients.

 

Long term, I may power this little system with an ornamental species to make management of the fish side of it a bit easier.

 

Gary

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Not looking for a particularly detailed answer at this point, but are catfish commonly raised in AP? I'm interested in BCotton's question as it related to what I also hope to do - raise fish that are adapted to the kinds of conditions I have (so i don't have to heat their water). Catfish aren't native here, though they've naturalized in the Sacramento Delta. We do have a native carp (Sacramento Blackfish) which would probably do well. I'm unsure of how viable Sacramento Perch are for AP/iAVs but I've heard on that definitive source, The Internet, that Sac Perch are good eating. I have no idea if fingerlings are commercially available, though...

 

I've mentioned elsewhere that I may start with koi (or goldfish) but if I can work up to edible fish, I'd like something that wouldn't struggle too hard with what we're working with here...

 

sorry, this is kind of just me thinking out loud, but any I'd be interested to hear y'all's opinions :)

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Hi Wendy,

I have read some of Jon Parr's blog from time to time, he maybe able to supply some fish stock. Not sure how close he is to you. http://www.fishnetaquaponics.com/fish.html

He is a big proponent of using a local fish variety in his AP systems.

Jon had given AQN a pretty I depth run down of a large Aquaponics operation that he had an interest in. Seems like a straight shooter. http://aquaponicsnation.com/forums/topic/8883-the-viridis-system/

Good luck!

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in my non-iavs quaponic systems i grow bluegill, crappie, large mouth bass, hyrbid striped bass, red eared sunfish, channel catfish and of course tilapia, goldfish and minnows. based on my experience with these fish if i were to attempt iavs in dallas, i will use bluegill. While they grow the slowest of all of these options they are by far the most tolerant to poor water conditions. The only time i ever lose any is in extreme cold (water is frozen) and extreme heat (very high 90's or 100 degree water temperatures) but of which can be avoided with good insulation and shade/protection. They even have a moderate amount of chlorine/chloramine tolerance like tilapia. 

 

Channel catfish grow very fast, So they can outgrow a small fish tank like an IBC relatively quickly. I very much like to raise them but I would rate them closer to HSB than anything in tolerance to poor water conditions. Their poor tolerance surprised me because when i try to clean them they will not die!! ice bath, spike to brain, decapitation and they are still flopping around and breathing. but they are one of the first to "cut bait" when something gets off kilter and the water conditions are bad for a few days

 

brian

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based on my experience with these fish if i were to attempt iavs in dallas, i will use bluegill. While they grow the slowest of all of these options they are by far the most tolerant to poor water conditions. 

 

Temperature is the only water quality issue that's like to impact iAVs.

 

Just as aside, I transferred the contents of my microFish Farm filter clean to the demo unit fish tank.  It was murky horrible stuff with loads of suspended matter.  Overnight, with about five pumping cycles, the water in the demo unit fish tank became gin clear again.

Edited by Gary Donaldson (see edit history)
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We're having a week with highs in the 100s (just nearing 40 C) and lows in the 50s (mid teens C)... and it's only June! I hadn't thought about insulating the IBC tank and wonder if I should consider it (and then look for something that can slip between the plastic tank and the metal frame).

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We're having a week with highs in the 100s (just nearing 40 C) and lows in the 50s (mid teens C)... and it's only June! I hadn't thought about insulating the IBC tank and wonder if I should consider it (and then look for something that can slip between the plastic tank and the metal frame).

 

You'll probably find it easier to attach something to the outside of the IBC Frame.  One possibility would be Dow Blue Board (used by some  DWC folks as rafts).  You could strap that to the outside and paint it for added durability.

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There is a reflective foil bubble wrap that I've used in the past to wrap around odd shaped tanks that might work for you.   Water tends to warm up slower and release heat slower than outside air temps.  A measurement around 6 -8 AM and again at 7-9 pm will tell you more about the actual water temp swings.  The more the water the less it will move, so 10 gallon setup will swing more than a 300 gallon setup.

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Hi Neighbor...

 

I know the feeling well

 

I would try to keep my tanks in the shade as much as I possibly can.

 

Keep fish that can tolerate higher temperatures...For as close a water temp comparison as I can think of to tlapia, I raised Barramundi In the summer, which is ideal for them but they don't survive well above a tank temp of 30.

 

I'd try what the others suggest plus...

 

If you are getting tank temps regularly above 30C and they are staying there for any length of time then I'd suggest a couple of things...

1. Try freezing quart containers of water or large ice cream containers of water then take them out of your freezer on the very hot days and dump them into your fish tank/s and see if that can drop the temp down a bit.

2. If the above doesn't work then a partial or complete water change over may be the only option to save your fish. I know you'll quite possibly knock your cycling around but you'll just have to recycle if you need to...

So if you can get a container/tank/s that will hold your fish water put them close to your fish tank and try pumping the water out and into the spare tanks. This is an emergency temporary thing to save you fish but it should work

 

I haven't had to do either yet but have come close once twice three or four times and will if I have to

 

I did lose a few tropical fish in my aquarium at home, but that went over 33 C and the others I threw into my aquaponic fish tank which was cooler overnight until they recovered...At that time my  aquaponic fish were fingerlings so the others did not get eaten.

 

Cheers.

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If my water gets too warm I add a fan that blow across the top. It helps the evaporation by bringing in fresh air. It is a silly option but it seems to work for me. My water temp is air temp and it is about 38C now.  Both lids are open and maybe tomorrow the fan gets added again till the heat wave is past us or it rains.

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If my water gets too warm I add a fan that blow across the top. It helps the evaporation by bringing in fresh air. It is a silly option but it seems to work for me. My water temp is air temp and it is about 38C now.  Both lids are open and maybe tomorrow the fan gets added again till the heat wave is past us or it rains.

 

Have you ever wondered why they use a wet-wall in a greenhouse?

 

If your working in the hot air outside, and you walk into the shade, the air and you get cooler? Why?

 

If you take the temp. of water landing at the bottom of a waterfall and compare it to the same water before going over the falls, why is there a difference in temps?

 

You have 1/2 the answer in how you are applying it in the horizontal plane, what you need to do is put the same principles in the vertical plane.

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Yes I agree Gary,

 

Sorry about that...So where are you at ATM with this project?

 

Cheers.

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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. 

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