HID Ballasts: The Quick and Easy Digital Ballast Guide
Last Updated: November 17, 2016
Lighting is one of the most important components of your indoor or greenhouse hydroponic garden. But lighting is nothing without a good digital ballast, the device that is actually running your precious bulbs.
As of 2016, the options are plentiful and making the right purchase can be a daunting task. I know that delving into a new subject empty-handed can be a chore, so I've decided to simplify this process to save you time and money. Most importantly, I want to make sure you can get back to focusing on what matters the most: your plants.
I’ve gathered all of the research and recommendations into this neat little article. It covers the basics of HID ballast technology, the features to look for, and then a few recommendations as to the best HID ballasts on the market.
If you just want my recommendations for the best ballasts, check these two out:
Best Overall Digital Ballast
This is the best digital ballast I can possibly recommend: excellent price point, will fire 600 and 1000 watt MH & HPS bulbs. comes with a lit digital screen, a built-in timer, and other high end perks.
Best Bang For Your Buck
Has features and quality for a price no other ballast can beat. Lacks some of the highest end features, like support for DE bulbs and only a 5% bulb boost, but that’s nothing to complain about at this price.
If you’re interested in learning a lot more about electronic ballasts, what makes a ballast digital, key features to look for, and want to compare different options, keep on reading!
What is a Digital Ballast?
Because of the specific requirements of High Intensity Discharge (HID) bulbs (includes HPS and MH bulbs) ,they need an electronic ballast to supply them with power and manage their capabilities.
The ballast takes your input voltage and current and regulates it into pulses within specific frequencies to enable your lamp or bulb to run efficiently and optimally, regardless of voltage fluctuations outside of the system.
The best digital ballasts should be able to keep your HID bulbs running optimally even if your input voltage suddenly changes.
Usually ballasts look like a rectangular shaped box covered in aluminum heatsinks with electrical connectors, cables, knobs and sometimes digital screens.
What makes an electronic ballast a digital one is that they contain a microprocessor. You must have a microprocessor in your ballast — it makes a huge difference. The microprocessor enables the ballast to run MH and HPS lamps, make necessary adjustments based on the type of lamp it is running at a given time, and sometimes even compensate for lamp degradation.
Features to Look for In Your Digital Ballast
Dimming is easily the most basic feature to look for in a ballast. It enables you to run your light at a lower wattage in order to save power, or to adjust your light intensity depending on your plant needs and preferences.
A good ballast should allow you to dim your lights to at least 50% of power. More advanced ballasts allow a far greater range of adjustment, and some offer this feature digitally rather than with the usual adjustable knob.
The best ballasts out there come with extensive bulb protection features, some of these include:
- Ignition Voltage Control
- Line Quality
This depends primarily on the quality of the specific ballast we’re using and secondarily on the quality of your electrical connections.
Lower quality ballasts have been known to go defective within 6 months. Higher quality ballasts, on the other hand, could last for over 5 years while keeping your bulbs running optimally. Some have been known to last for over 10 years.
A high quality ballast should handle voltage fluctuations without any noticeable changes in the behavior of your grow lights.
Radio Frequency Shielding
Not all is happy and well in Ballast Land. Due to the nature of how ballasts work, and if they’re built without proper shielding, they will create a noticeable amount of Radio Frequency Interference.
This means that they will broadcasting a radio signal within certain frequencies which can interfere with other electronic devices, radio enthusiasts, or get yourself some unwanted cable company visits because they traced the signal back to your garden.
The best solution is to avoid the problem beforehand by making sure your ballast is built with proper RF Shielding.
For further reading, visit https://blog.1000bulbs.com/home/stopping-fluorescent-ballast-emi
For us, a flexible ballast is a ballast that allows you to simplify your garden. A ballast you can use under different circumstances with minimal hassle.
A flexible ballast should be capable of:
- Running different wattage bulbs: Buy a ballast that can run at least 2 types of bulbs. For example, both of the recommended ballasts can run at least 600 watt and 1000 watt bulbs.
- Running different types of bulbs: Being able to run both HPS and MH without the need for two separate ballasts.
- Support for Double-ended (DE) HPS Bulbs: These bulbs last almost twice as long as normal HPS bulbs, and provide significantly more light to your canopy. These are the pinnacle of HPS efficiency, although not every ballast supports them.
- Boosting: Although some retailers use proprietary terms, what we call boosting is the capability to run a bulb over its specified power output. Usually the boost hovers around 10%, some even go up to 15%, which is actually very substantial.
With the lights and other equipment in your hydroponic garden, it's no surprise if your grow room or grow tent runs a little hot. And while that’s actually a good thing in colder months, it is not so good when your plants stop growing due to excessive transpiration.
It is normal for a ballast to get a little warm, but not so hot that you can’t even touch it! How are you going to shut it off if you’re going to burn yourself by touching it? This has been the case in the past with lower quality ballasts. Heat output usually isn’t a problem with higher quality ballasts.
This one should be self-explanatory. Normally a ballast should be pretty quiet. Some of the best ones are absolutely silent, while others come with small cooling fans that make little-to-no noise.
But sometimes lower quality or faulty ballasts will emit noticeable “humms” which can be very annoying for some people. Usually this is not something to worry about, but it shouldn’t be happening and is normally a sign of a loose transformer, loose screws or another faulty component.
Ballasts vs. Bulbs: Which to Spend Money On
The easy answer? Both.
The technical answer? Still both.
The "I’m trying to save money answer?" The ballast.
It's this simple: you shouldn’t be running high quality bulbs with a lower quality ballast, but you also wouldn’t want to run a $10 Bulb with your $250 ballast.
A good quality HID bulb should run you a long way without breaking down, but it is recommended that you change your bulbs at least once every year because they suffer from degradation due to their nature.
This means that as time goes on their PAR (Photosynthetically Active Radiation) output lowers. Sometimes, the bulbs even have changes in the spectrum of light they put out. So if you think your 5 year old HPS bulb is running just fine, think again!
This is why you actually can run standard bulbs on higher end ballasts. You’ll enjoy the safety and consistency of a good ballast and your pocket will thank you when you save 40 dollars on bulb replacement.
Note: Replacing your bulbs every 6 months is not at all necessary and depends highly on your application and needs. But if you're hoping to achieve the biggest yields and efficiency, you should consider replacing your bulbs periodically on top of using the highest quality ballasts.
An important thing to note is that using a lower quality ballast will lower the light output of even high quality bulbs by up to 10%. So remember that you should always match your high quality bulbs with a high quality ballast.
Digital Ballast Recommendations
Good job following the guide all the way to this point! You should now feel confident in making a solid ballast choice. Here is my list of the best HID ballast choices for HPS and MH bulbs. I considered overall quality, features, and finally price as my criteria. Most of these ballasts are very flexible and pack quite a punch at their own price range.
Best HID Ballast - Overall
This is the best digital ballast on the market right now. It fires 600w and 1000w MH & HPS bulbs, comes with a lit digital screen, a built-in timer, and other high end perks. All at a price point that isn't outrageous.
- Very high efficiency
- High end ballast at a relatively low price point
- Will run single and Double Ended lamps
- Pre-ignition self-diagnostic checks
Best HID Ballast - Honorable Mention
This ballast is for people that know exactly what they need and how to use it. It's the most expensive one on the list and has the quality and performance to back it up. It isn't as flexible as the Solistek, but if you want the highest quality money can buy, go with the Phantom.
Best Digital Ballast for the Money
The Purple Reign is a steal at this price. It's the best bang for the buck digital ballast on the market, easy. It packs a punch in features and quality at a price that no other ballast can beat. Sure, it lacks some of the highest end features like DE bulb support, and only has a 5% boost, but it's nothing to sneeze at.
Other Cheap HID Ballasts to Consider
Comes in 400, 600, and 1000 watt options. It's quite lightweight and sleek, partially due to the lack of extra features. Even so, it still has a 50% dim. Simply put, it gets the job done.
The Vivosun is cheap, lightweight, and no frills. It does dim and can be boosted up to 10%. Aside from that, it has the basic safety features that most ballasts come with and not much else. If you are looking for a super cheap HID ballast, this is the one for you.