Aquaponics Digest - Mon 01/05/98
Message 1: archives
from Miekal And
Message 2: Re: perlite post for Rebecca
from donald trotter
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| Message 1 |
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Subject: archives
From: Miekal And
Date: Mon, 05 Jan 1998 10:41:39 +0000
wondering if there has been an archives of posts established & what url
that might be at...
I'll try to post an introductory post in upcoming weeks
miekal and
--
Dreamtime Village website: http://net22.com/dreamtime
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Subject: Re: perlite post for Rebecca
From: donald trotter
Date: Tue, 30 Dec 1997 10:15:50 -0800
>Hi Rebecca!
Here is a perlite post that I sent a while ago. I'm not sure if is the one
that you were looking for.
Hi George!
Have you considered PERLITE? It is being used al over the world in
hydroponics and sooilless applications. I am including this website address
for you to browse and also some basic information on perlite use.
WEBSITE
www.cropking.com/cropking/cat22.htm
basic facts about Perlite...
Origin and Characteristics...
Perlite is not a trade name but a generic term for naturally occurring
silicous rock. The distinguishing feature which sets perlite apart from
other volcanic
glasses is that when heated to a suitable point in its softening range, it
expands from four to twenty times its original volume.
This expansion is due to the presence of two to six percent combined water
in the crude perlite rock. When quickly heated to above 1600=B0F (871=B0C), =
the
crude
rock pops in a manner similar to popcorn as the combined water vaporizes
and creates countless tiny bubbles which account for the amazing light
weight and
other exceptional physical properties of expanded perlite.
This expansion process also creates one of perlite's most distinguishing
characteristics: its white color. While the crude rock may range from
transparent light
gray to glossy black, the color of expanded perlite ranges from snowy white
to grayish white.
Expanded perlite can be manufactured to weigh as little as 2 pounds per
cubic foot (32kg/m3) making it adaptable for numerous applications.
Since perlite is a form of natural glass, it is classified as chemically
inert and has a pH of approximately 7.
Uses for Perlite...
There are many uses for perlite. These uses can be broken down into three
general categories: construction applications, horticultural applications,
and
industrial applications.
Construction Applications
Because of perlite's outstanding insulating characteristics and light
weight, it is widely used as a loose-fill insulation in masonry
construction. In this
application, free-flowing perlite loose-fill masonry insulation is poured
into the cavities of concrete block where it completely fills all cores,
crevices, mortar
areas and ear holes. In addition to providing thermal insulation, perlite
enhances fire ratings, reduces noise transmission and it is rot, vermin and
termite
resistant. Perlite is also ideal for insulating low temperature and
cryogenic vessels. When perlite is used as an aggregate in concrete, a
lightweight, fire
resistant, insulating concrete is produced that is ideal for roof decks and
other applications. Perlite can also be used as an aggregate in Portland
cement and
gypsum plasters for exterior applications and for the fire protection of
beams and columns. Other construction applications include under-floor
insulation,
chimney linings, paint texturing, gypsum boards, ceiling tiles, and roof
insulation boards.
Horticultural Applications
In horticultural applications, perlite is used throughout the world as a
component of soilless growing mixes where it provides aeration and optimum
moisture
retention for superior plant growth. For rooting cuttings, 100% perlite is
used. Studies have shown that outstanding yields are achieved with perlite
hydroponic
systems. Other benefits of horticultural perlite are its neutral pH and the
fact that it is sterile and weed-free. In addition, its light weight makes
it ideal for use in
container growing. Other horticultural applications for perlite are as a
carrier for fertilizer, herbicides and pesticides and for pelletizing seed.
Horticultural perlite
is as useful to the home gardener as it is to the commercial grower. It is
used with equal success in greenhouse growing, landscaping applications and
in the
home in house plants.
Industrial Applications
Industrial applications for perlite are the most diverse, ranging from high
performance fillers for plastics to cements for petroleum, water and
geothermal wells.
Other applications include its use as a filter media for pharmaceuticals,
food products, chemicals and water for municipal systems and swimming
pools.
Additional applications include its use as an abrasive in soaps, cleaners,
and polishes; and a variety of foundry applications utilizing perlite's
insulating
properties and high heat resistance. This same heat reistant property is
taken advantage of when perlite is used in the manufacture of refractory
bricks,
mortars, and pipe insulation.
Please contact Redco II for more information regarding your particular
application.
Redco II / redco@earthlink.net
Back to Main
Organically yours, Donald W. Trotter PhD.
The Organic Gardener's Resource Centre
In a message dated 97-12-07 16:03:26 EST, you write:
>
>> Subj:
>> Date: 97-12-07 16:03:26 EST
>> From: gkunkel@cris.com (George Kunkel)
>> Sender: aquaponics-request@townsqr.com
>> Reply-to: aquaponics@townsqr.com
>> To: aquaponics@townsqr.com
>>
>> Two questions. First I grow nft lettuce in trays without any difficulty.
>> Yet when I try to grow spinach in the same system I get very mediocre
>> results. E.C. kept around 2, pH about 6.0 night temp about 62-64 [for th=
e
>> associated but separate system tomatoes]. Spinach [tyee] germinated in
>> oasis cubes, same as lettuce, but poor root system evolution in the tray=
s.
>> What to do? Next, in a separate house grow roses in containers with gra=
vel
>> and intermittent fertigation without problems but looking for an
>> inexpensive lightweight media to replace oh-so-heavy stone. The fired cl=
ay
>> material is of course great, but last time I checked it was unbelievably
>> expensive even in bulk. Freight costs are a consideration too [I live in
>> Harrisburg, PA ]. Any thoughts [hope]. Thank you, George Kunkel
>>
>
> George,
>
> A trip over to Hydrofarm in Bristol, PA (outside Philly) would
>probably be your closest to pick up a load of clay pebbles. You
>might want to try perlite. It's really light weight and grows tomatoes
>and basil like crazy.
> When is the last time you changed out your total nutrients? You
>may be missing some of the trace elements. If your night temp is
>around 64, how hot does it get during the day? For the most part
>the lettuce and spinach should do very well together with the same
>nutrient and temperatures.
>
>Carl
>
>Carl O. Anderson Virginia Hydroponics, Inc.
>(757) 490-5425 368 Newtown Rd. #105
>HYDRO4U@aol.com Virginia Beach, VA 23462
>Teacher Resource Center http://www.hydro4u.com
Donald Trotter
The Organic Resource Centre
293 Neptune Ave.
Encinitas, CA. 92024
curly@mill.net
1.888.514.4004
fax- 760.632.8175
Donald Trotter
The Organic Resource Centre
293 Neptune Ave.
Encinitas, CA. 92024
curly@mill.net
1.888.514.4004
fax- 760.632.8175
S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
Web page http://www.townsqr.com/snsaqua/
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