Opinions on re-sealing.

[Aquattro]

While the GE 1200 is stronger than regular silicone, it costs a bit more. When re-sealing, you aren't adding any strength, just a water seal, so you might as well just use regular silicone. GE I is still fine, and Home Hardware carries a brand that is safe for aquariums. It's labelled as 100% silicone, kind of a generic tube.