400 watt HPS and MH ballasts are a necessity for those using 400w grow lights. Whether you need a replacement or you are building your own HID grow light kit, this is the life source of your lighting system.

Here at Hydrobuilder, we carry the widest selection of 400w HPS and MH ballasts you'll find online. Find popular brands such as Delux, Phantom, Solis Tek, Sun System, and more!

Why do I need a 400 watt HPS and MH ballast?

The ballast is your power source. It is in charge of igniting your lamp, and keeping it running at a level that is safe for the bulb, extends it's life as long as possible, while still adequately lighting your plants. Without one, you would never get your lamp to spark, or if you did, it would burn too hot and blow up your bulb.

Which ballast do I need?

Ballasts can get a bit confusing, especially with the extensive collection we have here at Hydrobuilder. There are two types: Magnetic and Digital. For the sake of time, we won't go in depth on magnetic ballasts. They are slightly outdated, produce a lot of heat and noise, and don't run super efficient. We still carry them because some older fixtures rely on them.

Digital ballasts on the other hand run very efficient, don't produce much heat, and feature RFI shielding, preventing any radio or TV interference for you or your neighbors.

Make sure your ballast matches your grow light in terms of wattage and SE/DE. So if you have a 400w DE grow light, you need a 400 watt double ended ballast.

Still need help choosing a ballast?

If you aren't sure which 400w MH and HPS ballast is right for you after reading all this, give us a call and we will gladly help you pick the right one. Our experts are happy to help you, and we want to see you succeed!