Welcome aboard!! You will find tons of useful information to help you decide on what tractor is best for you. Don't be afraid to check out all the brands and test them out.
Water & Calcium....(very corrosive)
Water and anti-freeze
Water & Window Washer Fluid
Beet Juice
Rim Guard
The idea is to add weight via loaded tires. (and the weight is low and it does not take up your 3 point hitch as a ballast box / box blade would) (Also, many people use both loaded tires and a rear box)
Rim Guard has a nice page that explains how many gallons are needed for your tire size and what the added weight would be per tire