do you know what kind of silicone 2 they had used? what I used was the window and door, but I know there is kitchen and bath as well. this whole thing would be so much easier if I could just set up this tank, let it cycle and do it slowly but I am moving right away and am tearing down my 90 and using all the equipment, substrate, etc to cycle/seed the new tank. I will be moving the 90 over to the new place too, so if everything fails I can set it back up and move them back but it will definitely be stressful on the fish. and definitely not preferable. I mentioned in the thread I created about this issue that I have actually used silicone 2 on another tank I built and it has been in use for months with no issues and I have used it as a hospital/quarantine tank and lately ive been keeping wild caught plecos and shrimp in it. it's only roughly 20 g so I definitely used a larger ratio of silicone to volume so I would assume that it would have shown up there. as with your friend, a lot of what ive heard is almost instant deaths which I have seen none. makes you wonder