I have seen that plastic and wondered how it would hold up.I do have one suggestion for your next build,give the silicone more drying time before adding water. I usually lay the tank over on its side to allow the fumes to roll out and wait at least a week before adding water. That will assure the areas where the silicone is thickest to cure properly. I have ruined a couple of projects in the past because I was too eager to see it done
Good luck with it and don't forget to post some pic's