Here's where I get my watering supplies.

http://www.reptilebasics.com/rodent-watering/

I have had leaks but none of my rats or babies have drowned. I check the tubs often and can usually spot a leak early. Another issue is that sometimes lines clog and the water does not flow. Check your valves often and flush out your lines once per month. You can add a tiny bit of bleach to the water when you flush them. Tiny=capful in a gallon of water. Rinse well.