HOLD UP. Wait just one dog-gone minute. People I hate to break this to you but Karin is NOT being honest with you. It is clear to me after seeing all of the pictures of her tank that the REAL reason why this works so well is that she has somehow figured out how to train her snails not to crawl across the back glass. Think about it. Have you seen a picture of her tank with a snail crawling across the back? Of course not. That would ruin the desired affect. She has somehow trained her snails and she is not sharing this info. Before you go and spend all that time and effort you should think about how YOUR tank is going to look without trained snails. Its going to look STUPID. Its going to look like you have snails suspended in the water column. What are you going to tell your friends? Are you going to say something like 'my snails can actually swim'?
OK OK I'm jealous. Your background project came out great. Congratulations.
Off to a good start, do you think those LEDs will give off enought light?
I think it looks great, but you realize a cave would be dark. I don't think the card board looks bad at all. With the frosting it is pretty hard to see, of course it maybe different in person.
Neat idea!