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hideous
25-04-11, 04:40 AM
Hello All

I have been given some advise on lights for my grow but I have a few lighting questions.

1. with HID must the bulb and the ballast wattage match or can one be higher then the other?

2. What is the difference between a "switchable wattage" ballast and a "dimmable" ballast? (And why have I been told to avoid the dimmable?)

3. I will be using MH and HPS so I would want a ballast thats switchable between them. Some ballasts are switchable with a switch and some auto detect is this correct? And they can be Magnetic or digital? And if magnetic can it use CMH?

4. Whats a conversion bulb?

Mr_Bimble
27-04-11, 07:35 PM
1) YES - the bulb and ballast must be rated at the same wattage (but can be run +/- 10% - thats how the super lumen settings work).

2) I was told a switchable ballast is more efficient & safer than a dimmable one & they also run cooler by the local growshop.

3) Most modern ballasts will run MH or HPS - I've got a lumatec 250W/400W digital switchable ballast and it works fine with either type of bulb, I dont have the change any switches - just swap bulbs over and turn it on.

4 ) Dunno

Dunno about CMH bulbs either.

Digital ballasts are supposed to run cooler, quieter and use less electricity than magnetic ones and mine certainly does.