the bugs shouldn't leave the viv. i have never had any leave mine, but anything is possible i suppose. just be careful when you work inside the tank to make sure you don't get any on your hands or clothing. that's pretty much the only way they will get out since they can't climb glass. if you are doing an egg crate bottom, you don't need the hydroballs underneath. the hydroballs are used to create a drainage layer, and placing them UNDER the egg crate is just a waste of $10. as far as upkeep, clean the poop, change some of the water every couple weeks (make sure you dechlorinate!!) and you're pretty much good.