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Re: GH and green water




On Wed, 25 Aug 1999, Dave Whittaker wrote:
 
> I was surprised that no one commented on my previous post concerning
> the disappearance of green water subsequent to the addition of dolomite
> to three tanks.

Well, I meant to but I got distracted.

Phosphate combines with calcium to produce some pretty insoluble
compounds.  I thought that maybe by increasing the hardness you
precipitated or sequestered the phosphate so the algae could no longer
grow.  What I don't really understand is why that mechanism or any similar
nutrient-related mechanism would cause such a drastic disappearance of the
algae.  It seems to me like disappearance due to starvation should be
fairly slow - especially since the nutrients contained in the first
cells that die would be at least partly recycled and be available to
surviving cells.

Perhaps there are two or more mechanisms at work.  For instance, some
single-cell animals like paramecia are important algae grazers and act as
natural control on algae blooms.  Perhaps your green water tanks contained
a fairly delicate balance between the green water and the grazers.  If
something (like calcium making phosphate unavailable) slowed the algae
growth then the grazers could quickly wipe out the standing crop of algae
fairly quickly.  The grazing population would have died afterwords, as
well.


Just thoughts,
Roger Miller