Hi Leigh, AFAIK, the silicone sandwiched in between the glass panes
performs most of the structural integrity, while the extra bead run along
the inside is primarily to protect the sandwiched silicone from predators
(which you mentioned) and to provide a more uniform water-proofing
barrier. Essentially, your 29g could have no silicone bead along the
inside, (only the sandwiched silicone) and it would still be structurally
sound. If you have a lot of wear & tear on the bead, inspect the
sandwiched portion for bubbles (areas of weaker bonding and potential
water paths), and for any discoloration (water/humidity ingress with
algae growth or calcium deposits). If your sandwiched silicone is sound,
but the bead is very mangled, then your tank will just be incrementally
more vulnerable to a potential leak. If you ever observe the reverse,
where the bead is sound but the sandwiched silicone is in bad condition,
don't stand in front of that tank ;~)

Thanks. I'm not sure if I'm reassured or not. :-) The silicone between the
glass seems to be the same as always, but it's kind of hard to tell. It feels
good, but it's kind of hard to see.

I oughta move that bristlenose to another tank. I think he's the one chewing
on the seals. Only I'm afraid he'll do the same thing, and it will be worse if
there's ever a failure, because the other tank's larger. =:-O The other tank
has more algae, though, so maybe he wouldn't be driven to nibbling on silicone.


Leigh

http://www.fortunecity.com/lavender/halloween/881/