metal halide ballast question

[electrikat]

If you have a 250w ballast can you go to a 175 watt bulb. I know you can not go up in wattage but I would think you could go down in wattage. I would think you could drive anything up to and including the wattage of the ballast. Any ideas or facts would be appreciated. I am an aircraft electrician but am not so sure about these things.

 

[HoopsGuru]

I would not do it. Best case scenario is that the bulb may fire, but in all likelihood it would damage or greatly reduce the life of the bulb. 250w and 175w bulbs are not that much different in price, so I cannot really find a worthwhile reason to do it.

 

[Sam]

I am not sure that would be a good idea. Knowing that the bulb is rated at 175W, if you a 250W ballast to drive it, this may overdrive the bulb, potentially shorten the life of the bulb and may even do some damage to the ballast if electronic. Best advice I can give you is to check with the manufacturer of the ballast themselves. If the (electronic) ballast has the necessary circuitry to adjust to a lower wattage bulb, then you are good to go. Sorry cannot be of more help. HTH

 

[electrikat]

Ok you guys are correct. I went to dealers electric today and he said the thing about overdriving and blowing the bulbs. I really only needed to know because I want to get a mh for a 20 gallon, but want it to be big enough so I could move it to the bigger tank later if I get tired of the 20. 175w is really overkill for a 20 gallon but it's a little harder to find a 70w or 100w system online. I'll probably just go for the pc's. They could at least be converted to freshwater if I wanted to later on.