Re: [RML] Chemical dose

HH (Harro.Hieronimus at t-online.de)
Sun, 15 Nov 1998 13:27:59 +0100

Gary Lange schrieb:
> and show your work :-)
> 1) Formaldehyde at 1031 g/l = 1.031 g/ml (I love the metric system, gallons
> really suck)
> 2) You need 25 parts per million which translates to 25 milligrams per liter
> (1000 grams = 1 liter, 1000 mg = 1 gram 1 million milligrams = 1 liter or
> 1
> mg/liter = 1ppm
>
> 100 liters at 25 mg/liter = 2500 mg or 2.5 grams
> 2.5 grams needed divided by 1.031 grams/ml of formaldehyde = 2.43 ml
>
> I know Adrian will be careful with formaldehyde but for the rest of you that
> may be unaware this is really dangerous stuff. You can become incredibly
> allergic to it and like other chemicals can potentially cause you to pick up
> other allergies to unrelated proteins. It is also a known cancer causing
> agent. In the chemical industry most reputable companies require their
> workers
> to go to training classes on the proper handling and disposing of amounts even
> much smaller than the amount that Adrian is planning to use!
>
> Gary Lange
>
> ----------
> > From: Adrian Tappin <atappin at ecn.net.au>
> > To: rainbowfish at pcug.org.au
> > Subject: [RML] Chemical dose
> > Date: Saturday, November 14, 1998 9:51 PM
> >
> > I'm trying to calculate the dose rate of formaldehyde (1031 g/l) for
> > treating 100 litres of water at a delivered rate of 25 ppm.
> >
> > I came up 2.4 mil per 100 litres (approx).
> >
> > Would someone like to check if I have calculated it correctly
> >
> > Thanks,
> > Adrian.
> >
> > Adrian R. Tappin
> > "Home of the Rainbowfish"
> > http://www.ecn.net.au/~atappin/home.htm

Sorry, Gary, there's one mistake in your mail. Formaldehyde is never pure but a
40% solution at highest! So, to have 25 ppm you need 2.5 times the amount you
mention using the 40% solution.

Nevertheless, in one of the good working treatments using formaldehyde (FMC) you
use only 4 ppm i.e. 10 ml per liter.

Formaldehyde is said to be cancerogen and poisonous. However, there have been
pathologists and ichthyologists more than 100 years in age.

Best regards

Harro Hieronimus, Solingen, Germany
harro.hieronimus at t-online.de

****************************
No fish - no fun
****************************