Well, I can't add much to this technically, but I can a bit on the general aquarium issue. I agree with Erlik. Much as people who have them want to keep a pristine aquarium, it's virtually impossible. Plus, you've got a goldfish/koi in there. Them's dirty fish! They constantly muddle through the gravel for food particles which keeps stuff floating in the water. They're also avid vegetarians...they'd have a field day with a tank like this! :o) Just the bits of vegie matter they'd leave would leave some muck in the tank. It's hard to tell depth in this and because of that, it's hard to judge sizes of the fish. But, the fact remains that the guppy looks huge in comparison to the other fish. I'd make the discus larger, the goldfish/koi larger, the angel leave alone, the guppy and neons smaller. I also agree the sub needs fixing. Right now it just looks like one of those silly plastic aquarium toys. Last, I agree not being able to see the floor of the aquarium makes it a little hard to tell that's what it is. Have you considered something like having a faint reflection of a person in the "glass" of the aquarium? Maybe with a surprised look at seeing the sub? Or a child's hand pressed against the glass. Those could give the illusion of having a barrier between the viewer and the tank making it look more like an aquarium. And I'll stop rambling now. All in all, except for the plastic look of the sub, I think this is wonderful! :o)