I would suggest trying to build any system so that it's easy to do maintenance on while the plants are growing, for me that's very important. you don't want to dread doing a
nutrient change or checking pH because it's difficult to get to the
nutrients. Cleaning the
pump and reservoir should also be done regularly. I fear that your system although is a nice and compact design might be difficult to maintain. Like taking the lid off to get the pump out and cleaning the reservoir. I figure you will need to move the whole thing outside first to clean it out because you need to protect the carpet. This could be a problem because with the plants,
growing medium and nutrient solution in it, it will become to heavy to move around easily.
Without knowing all the details it is difficult to tell if the silicone will be enough to hold the jugs in place, especial when it has all the weight in it and you need to do the maintenance to the system. 100% Silicone does not have strength to it, though it's completely waterproof, it will peal off with pressure applied.
Just my two cents
