Metal halide questions

[jrflanagan]

I am looking to purchase a metal halide light for my planted tank, but I had a few questions.

What are the advantages/disadvantages to internal vs. external ballasts?

If I got a 250W fixture, can I replace the bulbs with 150W down the road if i want to?

What brand fixtures are the best?

Thanks

 

[Dan F]

Metal Halide ballasts are designed to run a certain wattage bulb - you usually can't change bulb size in a given fixture. I believe there are some newer electronic ballasts that can switch wattage, but most can't.

I would say that you almost certainly want a remote ballast. The fixture will be smaller, lighter, and less prone to moisture damage if you don't have the ballast integrated into it. It will also remove some of the heat from above the tank.

I like Blueline ballasts, but there are several good manufacturers. I would recommend Champion Lighting and Supply, they have a good selection and prices.

 

[dr_sudz]

External ballasts are also great because it removes a lot of weight from the fixture itself, I am guessing easy 25 lbs per kind of thing. Planted tanks are not overly in need of a metal halide tho, a good t5 fixture will do amazing. I have a 4 bulb system running and my plants (all of them) release O2 into the water all day long. its awesome to see the fizz coming out of the leaves.

 

[dr_sudz]

Ya you can't use the different wattage bulbs going from 175 - 250 the pin setting is way different, the 250 - 400 is closer and more likely to change that way if you could but if you are going to try that I would be looking to drive a 400 on a 250 but it changes the spectrum when your under/over driving bulbs, thus the effect will change. Mogul bulbs I believe are the easier to change like this the pin ones i can't recall but think there may be size differnce to make sure you don't screw up with it.

 

[jrflanagan]

Thanks for the advice.......I'll probably do a combination of T5's and halides. I like the halides for two reasons.....I've got a 29" deep tank and want to make sure I get plenty of light at the bottom for some hairgrass....and I want the shimmering effect.

What does everyone think of the Marineland or Current USA's Outer Orbit 150w/T5 combos? Someone today also recommended the Aquatic life fixture with the halides that you can rotate.

I'm planning on doing mostly swords, anubias and hairgrass.