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Re: Can someone check my math?
> Date: Tue, 10 Apr 2001 07:47:04 -0500
> From: Stephen Boulet <stepheb at comm_mot.com>
> Subject: Re: Can someone check my math?
> > Aaron Ivers wrote:
> > > Subject: Can someone check my math?
> > > I'm trying to introduce some more PO4 into my tank from AP's "pH Down", but
> > > would like someone to check my calculations before I start.
> > > The packaging says that it is 30% phosphoric acid. I'm assuming this to be
> > > H3PO4 (which should be about 97% PO4).
> > Sounds good.
> > > Is it acceptable to assume that 1 mL of this stuff then represents (1000 mg
> > > x 97% x 30%) or 291 mg of PO4?
> > Also sounds good.
Concentrated Phosphoric Acid is much denser than water (approx. 1.8(?)
for a 97% concentration) - a 30% sol. is approx. 1.2. This means that
unless your calculations include the differences due to the specific
gravity and if you are using a volume measurement (ml), you'll be adding
approximately 20% more phosphate than you think you're adding.