I wasn't that young, but we tried with a cheap plastic 20 gallon fish tank which gave us a bit more depth. It was before LEDs, so all we had were hot lights that wound up needing to be very close to the tank to get the amount of light needed. Over the course of the day, that heat actually melted the tank which meant we no longer had a 20 gallon tank but whatever the volume was below the melted part where it would start to leak.

I love your attempt at a practical to that level. I have one that I'm still working on with long exposure timelapse and motion control, but I just can't ever get my schedule to let me do it. I have models of flying saucers with little aliens at the helm that I've rigged up with LEDs connected to an Arduino. That also controls the motion control slider I have, and the camera shutter. The idea was to turn on the UFO lights for a very short duration while the shutter is open to keep from over exposing during the long exposure to capture the night sky in the background. There is no point in doing the shot, except just because. I have the problem of when I have free time, the weather is shite or the wrong time of the year for the part of the sky I want.

I love that story. It illustrates perfectly what fascinated me so much about visual effects as a kid, and maybe also why I lost some of that fascination when CGI took over. Even though I was also very interested in computers back then (and I really loved Tron).

There was so much creativity involved and out of the box thinking about physics and time and optics, to craft something that in the end resulted in a nice optical illusion. Like a magic trick (interestingly, in German visual and special effects are (or were) also called "Filmtricks").

Now with CGI, everything is possible and paradoxically, that makes it more boring somehow. And sometimes practical effects still look better IMHO.