bigdaddy

iAVs Questions

53 posts in this topic

Hi

This flint grit might be a option as well

 

Hi again

#8 grade is 2,38mm ,  and clasified fine pebbeles, not sand, acording to the chart(pdf link I posted)

The chiken grit Birdman uses, is probably the flint type, see here : http://poultrykeeper.com/general-chickens/types-of-poultry-grit ,

the shell grit type, would degrade. and cause a lot of water tracking/cloging. do to the flacky shape, so no good in a sandfilter IMO

 The #10 grade is 2mm &  #12 grade is 1,63mm are both clasified sand, all 3 gradings will have wery different SSA

You can use the formula and fine the spesific SSA, but you will probbably get the spesific ssa, from the place that sell you the sand, so you don.'t have to guess or do the mats.

Once you have decided what grade you put (available for you) in your filter, you will know your filters SSA.

 

cheers

 

Cheers

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I found a source of washed, graded quartz sand in WA, though it does not seem that cheap!

http://www.cimonline.com.au/mineral-suppliers/

 

1T bulka bags cost $250 + gst, or 40 25kg bags cost $8 + gst.   Is that price what others in Aus pay?  I'm guessing 1T would fill a 500L GB.

 

 

 

 The spec is:

 

Graded Silica Gravels: Available in grey and C.R.S. (red). CRS Fines -1 + 0.500mm, -2 + 0.85mm, -3.2 + 1.6mm, -6.4 + 3.2mm, -10.6 + 6.4mm, -20 + 10mm and +20mm.

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Hi,

 

During this morning's chat with Mark, he reminded me that there is an organisation called the American Standard for Technical Materials (ASTM).  They have a standard - C33 - for construction sand.  That specification requires that construction sand will not contain calcium carbonate.

 

If a contractor builds a bridge or a hospital or anything else, he specifies this material....and that happens in Texas, Oklahoma or anywhere else.  The C33 standard is not only relevant to the US.....it will apply anywhere in the world that it is quoted.   Having said that, there are similar standards organisations in most countries.

 

Incidentally, that C33 standard is available for sale but you won't like the cost......but then you don't have to have the standard; you just have to know what it stipulates.

 

It follows, in my mind at least, that if you contact a sand vendor and ask (in writing) for sand which meets the C33 specification, and he supplies you with anything else, you have the grounds for a legal remedy.

 

By the way, Mark ordered “washed builders’ sand†(that's what it's called on the East Coast) for his projects.  He never quoted any other specification or anything......and he got the "correct" sand straight off the bat.

 

I suggest that anybody who is having difficulty with accessing sand of the correct type tries quoting this spec - and see how you get on.  Don't mention what you want it for.....just quote the C33 standard....and see what the vendor is able do about your request.

 

Gary

 

Hi Gary, Good advise,

 

What did you ask for in your area when ordering your sand?

 

Cheers.

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I found a source of washed, graded quartz sand in WA, though it does not seem that cheap!

http://www.cimonline.com.au/mineral-suppliers/

 

1T bulka bags cost $250 + gst, or 40 25kg bags cost $8 + gst.   Is that price what others in Aus pay?  I'm guessing 1T would fill a 500L GB.

 

 

 

 The spec is:

 

Graded Silica Gravels: Available in grey and C.R.S. (red). CRS Fines -1 + 0.500mm, -2 + 0.85mm, -3.2 + 1.6mm, -6.4 + 3.2mm, -10.6 + 6.4mm, -20 + 10mm and +20mm.

I've seen a lot of so-called specification formats in my 32 years of addiction to sand. Never seen anything even remotely like that gibberish. I'm not going to risk an aneurysm attempting to decipher that stream of noise.

As to pricing, last I inquired (about 18 months ago), local suppliers were asking $35 to $40 cubic yard plus $0.75/mile delivered in a 8 yard dump truck. I'm about 120 miles away from the furthest quarry I'd consider (40 mi from the closest). Worst case cost to me = (8 x 40) + (0.75 x 120) = 320 + 90 = $410 = approx. $51/yd delivered. This is $5/yd more than crushed gravel, locally. In NC back in the mid 80's I paid just under $10/yd.

One cu yard is enough for 3 square yards of growing surface. My cost would be $17 sq. yard.

Which is $20.33 sq meter.

E.g., tomato at 4 plt m-2, yielding 6 to 8 kg plt-1 in 3 to 4 months = rate of 96 kg yr-1 (+/- 10%), first year, w/o fish

How can anyone think that this is expensive? BTW, sand does not go bad or wear out on human timescales.

OTOH at 2700 lb/cu yard for dry sand: US$250/ton = US$338 cu yard (plus gst):

At that price, concrete would be $1000/cu yard plus labor.

That is criminal IMO. The construction mafia must be strong in WA.

Edited by Mark McMurtry (see edit history)

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Yeah - I had trouble understanding it too- when I rang the lady said we have

 

0.5 to 1mm graded

or

0.85 to 2mm graded

 

WOW -  by my calcs 1T is about 0.7m3 which is 1 cubic yard roughly speaking, but you can get it for $51/ cubic yard whereas I'm being quoted  $275.

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No, still not found a cheap suitably grain sized source. The gin gin quartz sample i tested was too fine. I think pool filter sand may be my best bet at this point. Though about to go out bush for 3 months so its on hold.

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Is there any way to get the silt/fines out of the water when using unwashed sand? I washed the sand myself, but apparently not well enough. Thanks in advance!

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Hi ph0rque,

 

Welcome to APN.

 

The Bucket Tests on my YouTube channel will allow you to determine if the volume of silt or fines is going to impact drainage.  If turbidity is the only problem, then the water will clear up when the biological activity starts in the furrows.  Once biofilm starts to form in the furrows, it will filter out fine material that is suspended in the water.

 

 

Gary

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Hi Gary,

 

Where did you eventually get your sand from for your iAVs system?

 

Cheers.

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On 5/23/2016 at 2:14 PM, mattyoga said:

I found a source of washed, graded quartz sand in WA, though it does not seem that cheap!

http://www.cimonline.com.au/mineral-suppliers/

 

1T bulka bags cost $250 + gst, or 40 25kg bags cost $8 + gst.   Is that price what others in Aus pay?  I'm guessing 1T would fill a 500L GB.

 

 

 

 The spec is:

 

Graded Silica Gravels: Available in grey and C.R.S. (red). CRS Fines -1 + 0.500mm, -2 + 0.85mm, -3.2 + 1.6mm, -6.4 + 3.2mm, -10.6 + 6.4mm, -20 + 10mm and +20mm.

Yeah same price around here in Adelaide South Australia.

18/40 grade semi oblique quartz silica premium kiln dried sand about $260.00 for a bulka bag or $8.00 per 20 kg bag GST inclusive. Plus delivery.

Surely there's a cheaper way to do this.

Cheers.

Edited by bigdaddy
Added some extra text (see edit history)

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17 hours ago, bigdaddy said:

Yeah same price around here in Adelaide South Australia.

18/40 grade semi oblique quartz silica premium kiln dried sand about $260.00 for a bulka bag or $8.00 per 20 kg bag GST inclusive. Plus delivery.

Surely there's a cheaper way to do this.

Cheers.

You'd be able to buy that same sand in bulk (sans the bulka bag) and it's going to be cheaper again.  

I can buy sand of the right spec in Queensland for $66 per tonne.

Also there is no requirement for the sand to be kiln dried - just washed and graded.  In South Australia, my main concern would be that it's inert.  Much of the rock there is going to contain carbonate which is not inert.

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Hi Gary,

Specifically what sand did you ask for. I know you asked for filter sand. I did that and they said this is the sand they use in a lot of filters.

Cheers.

 

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Actually, I just presented them with the basics.....inert (silicon dioxide), washed and graded sand with a particle range of predominantly 0.6 to 1.2mm.

It's called various things in Australia......top-dressing sand, construction sand, etc.  The important thing is not the name but the specification.

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Hi everyone,

In an above ground tank and grow bed setup, where is the ideal place to put the inlet to the grow bed?...On top or in the bottom of the grow bed?...

Cheers

 

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Hi BD

The inlet to the growbed is allways placed on top in iAVs 

cheers

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Hi again

The water is supossed to be evenly spread out on the top surface, and then percolate down thru the sand,

How would you make that happen, with the inlet located below the surface (top) ?

cheers

 

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Hi everyone,

  • After growing products like, lets say tomatoes, which have a large root system. In my mind it stands to reason, after removing the plant itself you be meticulous in removing the root mass from the grow bed. Is it necessary and why? If it is necessary, do people have any easy way of doing this, or is it just one of tedious jobs, with no better way, which has to be done?
  • At the time of removing roots, providing it is necessary, what other sand/sand grow bed maintenance should be done in order to prepare for the next growing season?

Cheers.

early and GaryD like this

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Keep in mind my experience is limited.   I just scooped out some sand out of my outdoor sandbed to put in my new indoor setup I'm working on.   There was some residual organic matter from the tomatoes, squash,  eggplant in the sand. This was concentrated in the top 1/2 inch or ~ 1 cm of sand. My sand bed has laid fallow for almost a year and weeds were growing up in it, but due to it being sand they were easily picked out of it.    I don't see it being an issue as long as you dig up the main rootball when pulling up the old crop.

After learning about glomalin,  which is a byproduct of fungus consuming root material , I suspect the little bit of organic residue left behind will actually be beneficial to the system's future growth.   Only by engaging in  a little try and see long term; will we really be able to answer the questions of long term effects, though.   I do know reviews were mixed on gravel grow beds as to whether organic matter accumulated to a point that caused problems.  I suspect the same increased surface area that provides greater growth will also increase breakdown of residual matter.

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Hi BD

 

12 hours ago, bigdaddy said:

 what other sand/sand grow bed maintenance should be done in order to prepare for the next growing season?

Cheers.

Fix the sand bed surface (ridge/furrow)  after removing the crops, so that the flow patern gets right again

cheers

 

 

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23 hours ago, bigdaddy said:

Hi everyone,

  • After growing products like, lets say tomatoes, which have a large root system. In my mind it stands to reason, after removing the plant itself you be meticulous in removing the root mass from the grow bed. Is it necessary and why? If it is necessary, do people have any easy way of doing this, or is it just one of tedious jobs, with no better way, which has to be done?
  • At the time of removing roots, providing it is necessary, what other sand/sand grow bed maintenance should be done in order to prepare for the next growing season?

Cheers.

The root mass of tomato plants grown in sand is much smaller than those grown in gravel.  The plants are easy to remove when it's time to replace them with other plants.  Just remove any visible plant debris and, as Ande has suggested, you simple reshape the furrow ready for the next planting.

Gary

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Hi again,

We have a hot dry summer, occasionally exceeding 40 C for a week on end, regularly 30 to 38 C and a cold wet winter. We don't get snow, but it can get wet cold and windy occasionally, similar to the mediterranean climate, therein lies the problem. My tanks will be outdoors and so will my growbeds. I have succesfully grown Barramundi through the winter, but do not wish to do that again but have been also successful in doing 6 months barra and six months rainbow trouts.

I would like an all rounder (if there is such an animal) which does not require to much water temp management, and is easily available. with it'[s food also being easily available.

  • What fish do people suggest?
  • What food do people suggest?

Cheers.

Edited by bigdaddy (see edit history)

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