Re: [APD] Barr Method Question

["S. Hieber" <shieber at yahoo_com>]

I think that's right. I was only saying, in effect, you're
continually dosing nitrates when you feed the fish and with
lots of fish (food/poop), the frequency of changes matters.

One could take that back to the way you presented it, by
factoring in the food/poop as the total dosing. I guess
that's what you were saying below. But it's hard to know
precisley what that is. YOu could measure nitrates daily
and develop a good estimate for a given tank. But the easy
way to deal with it is to do the changes often -- as Tom
says, "reset" your tank.

Scott H. 


--- Andrew McLeod <thefish at theabyssalplain_freeserve.co.uk>
wrote:
> On Fri, 5 Dec 2003 15:11:25 -0800 (PST), S. Hieber
> <shieber at yahoo_com> 
> wrote:
> 
> > It would seems that holds only if the only nitrate
> source,
> > for example, is the chems you're dosing. Lots of fish,
> > complicates things and the frequency matters, just in
> the
> > sense that, if you wait too long between changes and
> the
> > nitrates keeping climbing, well, the inevitable end
> isn't
> > pretty.
> >
> > Scott H.
> >
> > --- Andrew McLeod
> >>
> >> The frequency of your changes is irrelevant to the
> final
> >> level of nutrient
> >> you will have AFTER each change
> >> and fertilisation, but to avoid spikes change water
> >> regularly.
> >
> > =====
> > S. Hieber
> >
> 
> That was the (horrendously inaccurate) assumption I was
> making. But if you 
> were adding 10mg, and the plants took away 6mg per
> interval of water 
> change, then you could simply assume you were adding 4mg
> and the method 
> would work. Presumably by maintaining a constant nutrient
> level level, 
> constant fertilisation and regular measured water changes
> you could find 
> the amount added/removed by fish/plants per unit time.
> I was about to ask how much nitrogen fish pooped and
> plants removed, but 
> then I realised that nitrogen inputs (food, fertilisers)
> must equal 
> nitrate out (water changes, plant matter), if you could
> that out.
> That's assuming that aquatic plants don't absorb
> atmospheric nitrogen, 
> like terrestial legumes (says my hazy knowledge of GCSE
> biology). Do they?
> 



=====
S. Hieber

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