I agree with Alicewave, I wouldn't use anything like CLR on my herp enclosures, especially in something they drink out of. Like Silkie said, vinegar works great! It takes off the heaviest mineral scale in no time at all, is very safe (hey we eat the stuff!), and also kills bacteria. To super clean enclosures, I use a spray bottle of vinegar and follow over top with a spray bottle of peroxide. Both very safe ingredients, and when used in this matter kill more bacteria than bleach!