splitting wattage of 400W ballast?

[ltjguy]

Ballast question. I have a pulse start 400Watt ballast that I am going to retro-fit sockets into a Hood with. I only have a 55Gal reef tank. My question is can I add wiring to the ballast so I can split the wattage between two mogul sockets for say 2x 125Watt bulbs? With my PC lights (4x 55W) this would give me a total of 470 watts and give me 8.5 watts per gal. Will it work to split the wattage? Should I go with 2x 100watt bulbs instead? this would give me 7.5wpg. I have some softees, anemones and plan to add some sps and a clam.

Please help

[Reefland]

Hi ltjguy, Welcome to Reefland!

You cannot split the wattage from a single ballast to burn 2 bulbs, it simply doesn't work that way. If you want to burn 2 metal halide bulbs, you need 2 seperate ballasts (or 2 ballasts inside of 1 casing). There is no way around it.

[ltjguy]

Why is this?
So, if I can't split the watts can I use a lower wattage bulb? I know you can with regular light fixtures. Or,are metal halides just different all together and you can't use a 250watt bulb with the 400watt ballast?
Thanks for the quick reply
ltjguy