Aquaponics Digest - Thu 09/02/99
Message 1: Re: Plastic cover, toxic?
from "Sam Levy"
Message 2: RE: Herbs post-harvest cleaning
from "Robert Vitale"
Message 3: FW: Herbs post-harvest cleaning
from "Robert Vitale"
Message 4: Re: Herbs post-harvest cleaning
from Adriana Gutierrez & Dennis LaGatta
Message 5: Re: Herbs post-harvest cleaning
from "William Brown"
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 1 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Plastic cover, toxic?
From: "Sam Levy"
Date: Thu, 02 Sep 1999 06:57:26 PDT
Tom--
you don't feed them in order to keep their oxygen demand as low as possible
(as well as ammonia excretion). this allows you to keep them longer w/out
asphyxiating or poisoning themselves.
my experience has been that if it's not toxic at the start (some of the
pvc"s need to have additives washed out before they're safe for fish
culture) they wont be toxic later. what can develop are things like
brittlness, tears, general degradation from exposure. (this is why it's
important to get a lining of correct thickness & w/uv stabilizers).
sam
>From: Bagelhole1
>
>one, why do you not feed the fish and
>two, I'm thinking that the sun's reaction with the plastic over time is
>what
>might cause some toxic release in the water.
> Tom O
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 2 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: RE: Herbs post-harvest cleaning
From: "Robert Vitale"
Date: Thu, 2 Sep 1999 10:21:26 -0700
I cannot find the ref books dealing with exact dosages but any good health
food store will have a selection dealing with Hydrogen Peroxide.
Do you have info about the use of Hydrogen Peroxide, concentration in water,
how long it should stay on leave etc.
Claude
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 3 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: FW: Herbs post-harvest cleaning
From: "Robert Vitale"
Date: Thu, 2 Sep 1999 10:42:47 -0700
Just a update to what I just sent, vinegar is not as harsh to leafy item,
H P works better on hard fruits
Bobv
-----Original Message-----
From: Robert Vitale [mailto:rvitale@dnet.net]
Sent: Thursday, September 02, 1999 10:21 AM
To: aquaponics@townsqr.com
Subject: RE: Herbs post-harvest cleaning
I cannot find the ref books dealing with exact dosages but any good health
food store will have a selection dealing with Hydrogen Peroxide.
Do you have info about the use of Hydrogen Peroxide, concentration in water,
how long it should stay on leave etc.
Claude
On Sep 1, 3:17pm, Robert Vitale wrote:
> Subject: RE: Herbs post-harvest cleaning
> If you have a choice between Chlorine of Food Grade Hydrogen Peroxide the
> peroxide is far the better choice.
>
> Bob Vitale
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 4 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Herbs post-harvest cleaning
From: Adriana Gutierrez & Dennis LaGatta
Date: Thu, 02 Sep 1999 14:03:20 -0400
I've located the publication on the use of chlorine for posthavest
handling. It is called Effective Sanitation of Packaging Lines, a 3
page document by Mark Ritenour, Steve Sargent, Jerry Bartz and Carlos
Crisosto, all from the University of Florida. Here is a brief summary
of their recommendations:
"The current recommendation is a coonstant maintenance of to 150 parta
per million of FREE (available) chlorine and a pH in the range of to 7.5
for all recirculated water."
"Chlorine solutions with ph above about 8 are relatively ineffective
against pathogens. Below pH 6, available chlorine is more corrosive to
equipment, activity is lost rapidly, and toxic chlorine gases are
evolved."
"After adding commercial chlorine, adjust the pH of the water to 7 by
adding either acid or base. Muriatic acid (HCL) or citric acid are
commonly used to lower pH while sodium hydroxide (lye) will raise pH."
"Exposure Time: High available chlorine concentrations kil pathogens
after short exposure times (< 1 min.) At lower concentration more
contact time is required to kill the pathogens."
"Amount of organic matter in the water(e.g. fruit, leaves and soil):
Organic matter ..can quickly reduce the amount of available chlorine.
Chlorine which combines with organic matter is no longer active...BUT
WILL STILL BE MEASURED BY TOTAL CHLORINE TESTING KITS."
"Maintaining Adequate Chlorine Concentrations: Chlorine must be added
to the water to replace chlorine lost to reactions with organic
matter..." This can be done with automated equipment or manually but
vigilance is required as the status of the water can change rapidly.
Samples should be taken at least on an hourly basis.
"Use self-cleaning screens in dump tanks to remove large debris."
"Drain the tank at the end of the day (consult local regulations for
disposal of chlorinated water.)
> Does the publication address whether or not the chlorine
> > strength measured is TOTAL or FREE?
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 5 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Herbs post-harvest cleaning
From: "William Brown"
Date: Thu, 2 Sep 1999 06:25:44 -1000
The archives have quite a lot on the use of Hydrogen Peroxide. Latest
organic pest killer is PerOxide know as Zerotol and ... (forgot the newest).
William Brown mahiwai@cmpmail.com
----- Original Message -----
From: Robert Vitale
To:
Sent: Thursday, September 02, 1999 7:21 AM
Subject: RE: Herbs post-harvest cleaning
> I cannot find the ref books dealing with exact dosages but any good health
> food store will have a selection dealing with Hydrogen Peroxide.
|
