I know there is alot of discussion on substrate already. This is directed toward someone with a bigger collection. I currently use newspaper. While is free and clean, it does mean i have to be on top of my maintenance. I've had instance of not being able to change out the wet paper and it turn into a disgusting wet mass that stuck to the tub and won't come off. Looking to expand my collection and I'm looking at the possiblity of using different subtrate. I want something that I can quickly spot clean without having to clean out the whole tub. I've look at many of the commonly use subtrate, like cypress mulch but it seems to get really messy and gets everywhere. Anybody with large collection and have experiment with different subtrate can give me any suggestions? This is for rack system btw so it should hold humidity relatively well?