Q1. It will not help keep up the pH, Ca and Alk. It does not dissolve unless the pH falls,
for x number of reasons. It my add a tad to the pH, Ca and Alk but in a trivial,
depending. In short time it will be coated bacteria and organics and all that will stop,
unless the pH falls much lower. Do not worry about it.
Q2. Ca and Mg will precip onto some of it initially, if it is aragonite, less if calcite
and more so it dolomite. However, such Hi-Mg Calcites will just go right back into
solution. Again in a short time it will get coated with bacteria and organics and this
will also stop
So don't worry about any of this
Kim said this
"Now if you are trying to run very very high calcium and alk. The CA
will precipatate out of solution"
This has nothing to do with the sand/say but does happen, it is called abiotic precip, aka
hard water deposits. All tanks have some, like the heaters and at the water-air interface
and sometimes lower on the glass. On fresh sand it can also happen more so, as Kim stated,
as the Ca has a greater affinity to be attracted to a similar surface chemistry. However,
again on the sand, organics and bacteria will stop this once coated.
--
Boomer
WCWing@nospamChartermi.Net
Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS
If You See Me Running You Better Catch-Up
"Thomas Bartkus" <thomasbartkus@comcast.net> wrote in message
news:pan.2005.10.01.16.55.45.93346@comcast.net...
: Okay - I'm confused.
:
: I *do* want to use calcium carbonate based sand because -
: It will help keep up the calcium & alkalinity & pH & trace elements as the
: sand slowly dissolves into the water. AND it won't scratch the glass like
: a silica sand.
:
: I *don't* want to use calcium carbonate based sand because -
: Calcium will preciptate out onto the CaCO3 sand and cause the
: alkalinity and pH to drop. I will have a heck of a time maintaing calcium
: & pH. Better to use a neutral silica or perhaps aragonite sand.
:
: What to believe?
: Thomas Bartkus
: