Magnetic Vs Digital Ballast: Which is better?

What does a Ballast do?

The job of ballast Is to simply reduce the amount of electricity that is travelling through a given electrical circuit. It will limit just how much energy can travel through at once to ensure that this level does not exceed the limit of the light bulb.

If un-regulated, you could be looking at bulbs not performing correctly, burning out or in some cases actually exploding. Agreed, this is something we want to avoid, and so ballasts are a necessity in any grow room set-up.

There are two main types of ballasts that are used in grow rooms everywhere and there’s always the question of which to choose: magnetic or digital?


Magnetic ballasts have been used for quite a while, , they’re still used by many as a tried and tested technology. Magnetic ballast has a core made out of steel plates which are wrapped in a copper wire coil – this creating a magnetic field. This helps to regulate the initial electricity current given so whatever is being powered does not surge all at once!


Digital Ballasts on the other hand, are a newer technology, instead use electronic circuitry to regulate the amount of charge given, bringing more efficiency with little heat. Solid-state electronic circuitry and microprocessors mean the ballasts can be customized to create the optimal levels for different types of lamp and different wattage.



Magnetic ballasts are heavier and more bulky than the new type digital ballasts have been designed. Now, this might not matter to you, but it’s something to think about if weight is a consideration. Heat can be a problem with magnetic ballasts, and you’ll find that they can be quite hot to touch after running for while. As well as this, they will run with a slight humming sound, thanks to the inside components. This can get louder over time and use as they wear down. To mitigate this get a soft fabric and double layer it, add 2 bricks face down and place the Ballast on it you will find the humming sound is nearly not existent.

Digital ballasts have the option to adjust the wattage they are running at. It means you can use either a HPS or MH lamp with the same ballast, and even change between 400w lamp and 600w lamp for example. This is a great investment as it really does save money in the long run.

Radio frequency interference is a real concern when running digital ballast. Magnetic ballasts do not cause this issue.


Magnetic Ballasts

  • inexpensive to buy;
  • overall gives a lower intensity output,
  • Extends the life of bulbs;
  • Doesn’t produce radio frequency interference.


  • Heavy
  • Much less efficient;
  • Can be noisy;
  • The casing can get very hot to touch after a couple hours of use;
  • Will only accept bulbs of specific wattage.

Digital Ballasts


  • Smaller and lighter in weight
  • Much more efficient;
  • silent running;
  • Most are customizable with dimmable option giving the grower even more control!;
  • The overall intensity output is much higher


  • More expensive to buy;
  • Radio frequency interference can be a problem for yourself and your internet provider.
Author: Hydroponify

We know all things hydroponics.

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