Frank,
I reinforced the corner outside the tank because i had no access to the rear and I had to glue three plates in the corner (one of them on the bottom pane). In your case, the chip you noticed is not exactly in the corner, so you have to glue only pieces on the vertical panes, with the same thickness of these panes. In terms of resistance it doesn’t matter if you strengthen inside or outside the tank. Good work.
Teen,
As I said before I’m degree in Civil Engineering and my studies helped me a little bit to understand some physical and chemical parameters associated to the reef keeping, nothing more. Diving helped me too. As Sheeter-doc said, experience, trying new manners, reading a lot allow us to do this and look like a professional propagator. Net give us a good help. In my opinion to have success propagating corals you need to maintain a reef aquarium successfully for long before.
Cheers,