lighting question

[cathy joe]

does i matter if the light you have has one 250watt bulb or four 65watt bulbs. the reason asking is right now i have a light with two 65watt bulbs and was going to get like a 250watt mh light, but got talking to my lfs and found it to be cheaper to just buy another light like i have to get 260watt

 

[reefnut]

Yes there is a difference. A 250w MH will produce A LOT more usable light (PAR) than 260w of PCs. If you're looking to keep light demanding corals, clams or anemones I'd go with the MH.

 

[cathy joe]

i dont really understand. there is a difference between 250watt mh and a 260watt pc.
what is pc?
i have alot of mushrooms, star polyps, xenia, button polyps, orange cup, zoos, frog spawn.
what do you think i need?

 

[bang guy]

PC = Power Compact Flourescent.
MH lighting is a point source of light so it is very intense. Flourescent give off light the entire length of the bulb so they are less intense even if the total light output is more.
More intense light means it will penetrate deeper into the water and deeper into coral flesh as well to give more light to the zooxanthellae.
MH light is also easier to reflect into the water so more light from the bulb actually goes into the water. This is why MH has more PAR than PC. PC bulbs are configured in a way that is difficult to capture all the light and point it into the water.
Your current corals will likely thrive with either type of lighting so if it's cheaper to go with the PC then I don't see a problem. If you're ever going to stock more light demanding corals like Acropora or Tridacna Clams then now might be the time to get the MH.

 

[cathy joe]

thanks for the help