"McEve" wrote in message
...

Hi all,

I buildt a cave from ceramic slates for my catfish, gluing the pieces
together with silicon. I used casco transparent glass silicon, it has the
number 2985 on it. It says on the tube it's meant for aquariums.

That's fine, normal silicon contains a mould resistant agent that will kill
any bacteria and therefore is not suitable for fishtanks, but people have
gotten away with making tankt from them for years though.


However, I'm a bit concerned becuase now after 24 hours I can still smell
the silicon, a rather unpleasant odour. I'm reluctant to put my piece of
art
into the fishtank becuase of this smell :P Have I used a potentially
dangerous silicon? should I wait longer than the 24 hours it says on the
package?

Depending on the thickness of the silicon it can take days even weeks for
the silicon to fully harden but normally it should be just fine after 24-48
hours.

The smell that comes from true silicon os actually acetic acid (CH3COOH, pKa
= 4.76) and could potentially lower the pH in your tank but for the small
amounts normally used I wouldnt worry to much...


The smell can take a few weeks to go away depending on the thickness of the
silicon applied and temperature, I usually wait 3-5 days after I do silicon
woak on my tanks before putting the fish / water back in just to be on the
safe side.


/Morten



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