We offer both the digital and magnetic ballast because some people want newer techonology and some want a better price.
Digital ballasts are newer offering less frequency interference, lighter weight, colder temperatures and dimmable features. This means you can purchase a 1000w electronic ballast and 1000w grow lamp then run it at 500 watts when its on the 50% setting.
Magnetic ballasts are older however less expensive. They do not have dimmable features and sometimes you need to flip a switch to let the ballast know when your bulb is metal halide or high pressure sodium. Other then that they work well and will power your grow light.
Chat with us or send us an email (we actually get back to you fast) if you have any questions.