Following are some helpful tips I've discovered and come across in my years keeping reptiles. I'm sure you'll find them helpful and interesting and if you have any helpful tips of your own, don't hesitate to send them to me. Good advice is priceless, especially in this hobby with so much still unknown.
The Problem: Mineral Buildup
If the water you use in your setups is hard water, you'll occasionally get some white mineral buildup from the calcium. This can be really hard to get rid of when you're cleaning. How do you get rid of it?
Vinegar! All of the animals must be in a separate tank at this time of course (the fumes could be deadly), but let vinegar soak on the buildup for a few minutes then it should scrub off. You must rinse the tank out several times very thourougly after this though because, again, the fumes of the vinegar could be very bad for your pets.
The Problem: Rusted Tank Top
Especially with aquatic frogs or any tank running a waterfall, your tanks screen lid may - over time - become rusty. You'd like it to look nicer, but you don't want to spend the money for a new top just because of that (and I don't blame you with how overpriced they can be).
Black electrical tape! Just line the sides of the tank with it. You can hardly see it - it looks like your screen lid is rust free!