I have to agree its not a good idea to drill your tank. Its best to have a predrilled tank or someone that knows what they are doing. I have a reef tank that has a sump under it and that means holes in the bottom! And oh yes if a clamp or seal gives way it can be a major issue! All i have to say thank god i have tile!!!!!!!! Cause oh yes ive had a couple of misshaps and ive been working with fish and tanks for over 10 years!

I have my cord on my pine snake enclosure going out of the top of the screen. I epoxied the exit hole so the snake cant escape that way. I have the cord hidden inside the setup by a foam crevice and plants. You cant see the cord behind the tank because of the foam background.

I think what you could do to hide the cord is covering it with plants or moss, a plants and moss covered pvc, or carve some styrofoam to look like wood or rock and hide the cord inside it. Oh and i just thought of something else! Find some hollowed corkbark at a petstore. You can hide the cord inside it and it looks 100% natural.