"Pszemol" wrote in message
...
"Wayne Sallee" wrote in message
...
I actualy add potasium silicate to my reef tank, to encorage diatom
algae. But no, silica sand does not disolve well in in the aquarium, and
nether does the silica glass that holds the water in.

It does not dissolve well - this is true...
But in chemistry there is not such thing
as unsoluble substances - water is so great
that *some* amount will always dissolve in it.
For some substances it will be much, like NaCl
or sugar. For some others, like CaCO3 it will
be only 400mg/l and then it stops, but still
some amount will find the way to the water.

Compare data for silicon dioxide (quarz)
with data for calcium carbonate CaCO3.
http://www.ilo.org/public/english/pr...8/icsc0808.htm
http://www.ilo.org/public/english/pr...1/icsc1193.htm
They both are listed as "insoluble", but we aquarists
know better than CaCO3 is in fact soluble in water and
we can get concentrations of calcium on the level of
450mg/l from CaCO3 without any big difficulties...

Also - there is silica available in sea water,
so it must come from somewhere - I would be
interested in knowing what is the source of
soluble silica in the sea water. Diatoms are
able to get it somehow for their own usage...

Interesting subject - I wish I knew more about chemistry :-)


This was something that I struggled with for months before setting up my
tank.
I was starting out fresh, so I said screw it...not the best attitude but
I guess I got lucky. I found some healthy debates on the Internet .
Since then I've topped it off lightly (1") with some prettier agra-alive and
Agronite.

I never tested Silica levels. I never saw a reason to. my corals are
healthy, my fish are healthy
and I don't have any Diatom Blooms. I also use RO/DI water, maybe that
helps.

Knock on wood !