One of the most important things for your canary is having a supply of good, clean water.  Never let the drinker (container for water) go dry.  If you have chlorinated water, keep a pitcher of it in the refrigerator for 24 hours before serving it to your canary, so the chlorine can dissipate.  Chlorine kills germs, which usually is a good thing, but it also kills beneficial bacteria that is in your canary's gut.  It is better to use water that has no chlorine for your bird. 

If you change cages or types of drinkers, or when you bring a new bird home, be sure your bird can find the water and is drinking from the container.  A bird gets dehydrated very quickly.  If you aren't sure they are drinking from the container, place a small bowl of water on the bottom of the cage.  Although they may want to take a bath in it, this will provide them with water to drink until they are using the drinker.

Clean your drinkers often.  They easily become fouled with food particles that quickly spoil and contaminate the water.  Many a canary has become ill and even died because of bad water.  If you have a tube type drinker, purchase a bottle brush that will reach into the tube to properly clean it.  After washing in soap and water, disinfect the drinker by soaking in rinse water that has bleach added to it.  After the soak, thoroughly rinse and let dry

Adding a drop or two of apple cider vinegar to the water is helpful for their urinary tract.  If you use the vitamins that are added to drinking water, you must change the vitamin water daily.  Be sure and properly clean the drinker before you refill it.

It is very convenient to have more than one drinker that will fit in your cage, preferably drinkers that are identical.  The parts and drinkers will be interchangeable, and you can have a clean drinker ready to replace one you are removing from the cage.

Make your own drinker tray using a plastic utility basket.  Drill holes into a piece of plastic sign material cut to fit the basket.  I made this one and find that it really makes handling multiple drinkers convenient.