When you search Amazon for "chicken waterers" many different type of chicken waterers come up. Here are three things to keep in mind when choosing the best Chicken Waterer for you.
Size
Chicken waterers can vary in size. Super small ones for baby chicks all the way to 50 gallon DIY waterers. If the chicken waterer refills automatically then there is no need for a very large one. 2 gallon or 3.5 gallon sized chicken waterer will work great if it refills automatically.
Keeps Water Clean
Keeping water clean is very important to help with bio-security. One way to help keep the water clean is by using Poultry Watering Nipples. There are currently several styles on the market.
Vertical Poultry Nipples
These work great for baby chicks through adult aged chickens. If you have to manually refill your bucket then you are not able to sit your bucket on the ground to refill. Also if you have a small run/coop this style will require the waterer to be placed higher in order to reach optimal height for the chickens to reach the waterer. Also these can drip more which can create more unwanted moisture in the coop/run.
Horizontal/Side Poultry Nipples
These nipples work great. Less vertical space is needed because they can be placed on the side of a bucket or PVC. There is a slight lip that will catch most unwanted drips. Tapered threads seal better compared to the vertical water nipples. These water nipples are close enough to the bucket that if a heated element is included this style of water nipple will still work through the winter.
Drinker Cups
These drinker cup style are great for in the brooder as long as you can keep the wood shavings from collecting in the cup. These are not advised for winter use.
Winter Proof
If you plan to keep chickens year round and you live in an area where temps get below freezing during the winter then you will want a watering solution that will keep water from freezing. The Automatic Chicken Waterer has a removable cap in the lid that will allow for a heated element cord to be fed through. During the winter the waterer will have to be manually re-filled. The easiest way to refill is to place a funnel in the cap and pour the water in from another bucket or watering can.
If you are looking for a heated DIY option then checkout my Mother of All Chicken Waterer videos. It keeps the water heated and always moving. This works great for a winter watering solution for a large number of birds. Please note always check with an electrician before you start plugging in a heated element and pump on the same circuit. The heater in this video uses 1500 watts and I had to put it on it's own circuit. Let me know in the comments what you use for your waterer.
Summary
I have used several chicken waterers types and styles over the years. I have put that experience into the "Farmer Brad's Automatic Chicken Waterer" This waterer that I make uses side water nipples to minimize extra dripping in the coop/run. Refills Automatically when connected to a garden hose. It is made of BPA Free/Food Grade Plastic. Also easy to daisy chain two or more together with the quick connects and R/O tubing that it uses.