Chemical reactions with silicone?

[malawi2854]

Hello - this is a long-shot...!

I had the silicone on my tank fail a few years ago - on the bottom edge of the front panel - causing all the water to fall out extremely rapidly (as you might imagine!).
The tank builders replaced the front panel and added additional reinforcing strips all around the base of the tank. 18 months later - the same thing essentially appears to have happened again. The result was slightly less catastrophic this time - a slower leak. I won't get into any of that - that's for another day.

After a lengthy wait, the builders returned again, and this time replaced the entire tank, and steel stand. The whole thing was built on-site both times due to access issues. The tank is 200cm long x 65cm tall x 70cm deep.

The tank builder noted that the adhesion of the silicone to the (new) front panel appeared to be the issue - the silicone appeared to be in good condition - but it "peeled off" the glass suspiciously cleanly and easily.
Once he got the old tank back to his workshop, he additionally noted that this problem only appeared to be present below the gravel level - silicone throughout the rest of the tank seems unaffected - except below the gravel line, which is showing similar issues right around the tank (including those panels not replaced as part of the first disaster),

He is at a loss as to what could have caused the issue. He has spoken to the silicone manufacturers, and they are going to take a sample of the silicone for testing. They've also asked for details of everything I dosed to the tank. Fortunately, I keep quite meticulous records of this - so have provided the list of everything used, and from which manufacturers.

Sorry for the long intro - but I think it's important. My question is whether there is any known reaction with reef chemicals and silicone. I know how stupid that must sound - obviously everyone's tanks are held together with the stuff... but I just want to try and cover all bases.

It is interesting to me that the issue only seems to have occurred below the gravel line - perhaps a bacterial thing?

Would welcome any enlightened ideas!

 

[tzabor10]

No, I would bet silicone doesn’t have any reactions with a normal reef environment. Not sure what would cause the issue.

 

[Randy Holmes-Farley Verified Community Expert]

Nothing we use reacts with silicone. I expect that something, maybe just water, but perhaps other things too, crept into the interface between the glass and the silicone, weakening the glass/silicone bonds. I don’t know exactly what that might be, but ammonia is a possibility.