"Harry Muscle" wrote in message
...
"Charles Spitzer" charlie.spitzer@nospam. .com wrote in message
news:c51m8e$6bc$1@transfer. .com...

"Harry Muscle" wrote in message
...
"Charles Spitzer" charlie.spitzer@nospam. .com wrote in message
news:c51lec$677$1@transfer. .com...

"james" wrote in message
news:qlYcc.410$es.107@fed1read02...
In article c51hrb$5rf$1@transfer. .com,
Charles Spitzer charlie.spitzer@nospam. .com wrote:

neither the glaze nor the tile may be safe. there's a lot of
glazes
that
aren't food safe (contain lead, cadmium, etc) and could leach
metals
from
either a basic or acid solution in contact with it. you'd have to
find
out
what is in them from the manufacturer, and they probably don't
know
since
tiles typically don't have a msds.

Anybody selling a kitchen tile laced with toxic heavy metals is
just
asking for litigation...

not really. also, OP didn't state that they were kitchen tiles.
could
be
floor, bathroom, , etc. incidental contact with lead bearing
glazes
for
kitchen tiles wouldn't be ither. the OP is talking about
leaving
them
inside the tank, which is full contact forever.

they allow lead crystal to be used for decanters as long as you
don't
store
wine in them. long term contact with lead crystal leaches out the
lead
into
the wine. it's all a matter of how long the contact is.



But what if the tile doesn't have a glaze on it? What if it's solid
porcelain, with the color pattern embedded throughout the whole tile?

Thanks,
Harry


then it depends upon what is in the clay, which comes from the ground
and
has LOTS of different metals in it, or could even be a blend of
different
clays from different regions of the world. for sure, the tile
manufacturer
won't know that, or at least, they won't tell. i've never seen an msds
on
tile.



So in other words, unless I stick it in the tank and wait for my fish to
die, there is no way for me to find out if it's going to cause any
problems.

chances are it's safe. however, how much of a betting person are you? you
might try a piece of tile in a test tank with 1 fish and some inverts for 6
months. if there's no affect, it's probably safe. also water changes would
decrease the amount of toxins, if any.

Bummer. Maybe I should stick with using slate tiles.

isn't slate shale? a lot of shale comes from oil bearing rocks.

Thanks for the info,
Harry

P.S. Are porcelain sinks, toilets, etc. glazed? Or are they smooth and
water repellent naturally?

yes. if you turn your toilet upside down, you'd see unglazed places. maybe
the inside of the tank lid too. the item is made in a mold, fired and
cooled, the glaze is sprayed on, then fired again at a higher temp.