Lighting Question - Simple But Complicated

[sacramonel]

When dealing with the intensity of light and light fixtures I realize that Halides have the most intesity. I also understand that the intensity is required to reach deep into the aquarium. I assume that the higher the wattage = the more intensity = the deeper the light penetrates though the water? Ie a 150 MH penetrates x amount of inches while a 250 penetrates x+z.Am I correct in assuming this?

Secondly, I also understand that when dealing with SPS corals high lighting is required. I equate this with the higher intensity and everything I asked above. Am I correct here as well?

Finally if I am correct in the two above assumptions then will the next be plausible? In a 75 gallon reef tank, I plan on housing SPS coral. I plan on having the SPS on the Top portion of the live rock only. This equates to about 10-12 inches below the water line. Below the SPS line I will house assorted low light soft corals, polyps, and mushrooms. Would this be possible with a 260 watt PC light, and 150 watt metal halide lighting?

 

[SkiFletch]

Yes, higher wattage equals more Photosynthetically Avaliable (or active) Radiation (PAR) down on the corals. The reflector used with them also greatly effects the efficiency of metal halides, so don't totally skimp on the reflector if you want SPS.

As for a 2x150watt MH and 4x65watt PC setup this will be enough light. I'd offer two other simpler solutions that are equally effective:

2x250watt metal halide only
2x150watt metal halide and 2x54watt T5 with individual reflectors

PCs waste a lot of light because of their construction and inability to have good reflection. Lots of light is wasted bouncing between the tubes next to each other.

 

[sacramonel]

Excellent Thank you. I already have the PC and one 150 halide pendant so I'm going to stick with this. I'm only planning on having SPS cover one side of my aquarium. The other I am leaving for LPS and softies. And of course the polyps and mushrooms for the bottom.Oh and by the way . . it's awesome when the technical side of the hobby starts to finally click in your mind. Thanks for confirming what I thought was correct.

 

[SkiFletch]

No problem. One word of caution though... You'll REALLY notice the aesthetic difference between the halide on one side and the PCs on the other. The PC side will look really dim comparatively. That may not matter to you, but be prepared for it

 

[sacramonel]

Oh I notice it. I'm not too bothered by it now but I probably will be in the future. The MH I'm using is the viper.http/www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=15489&N=2004+113352

I really like it. and I like the snap on concept. I may get another one in a couple of months to balance out the other side.

But . . . before I do that. If I was to use your ideas above with the T-5's and two halides how would I go about doing so? I do not have a canopy in which to house them. I'm not great at DIY, but I have a cousin who is an electrician and he could rig something up if I asked him to.

 

[SkiFletch]

The bigger challenge is how to mount them... Tough when you don't have a canopy and aren't great at DIY. You can always hang from the ceiling or use shelving brackets off the wall behind it, but that can look tacky

 

[sacramonel]

Yeah that's my problem. I mean I'm not awful at DIY. I probably could come up with something, but what? Reef Central has a good DIY, I'l lcheck if there is anything over there.