Lighting Aghhh!

[Cat]

Im very confused. I have a freshwater tank Im converting into a reef tank. Its a nice modern corner tank and it has a built in hood with two 22" flurescent strips and ballasts built in, the lights are not powerfull enough I know so I went out at the weekend and bought two 'Aqua white' High intensity Daylight fluorescent tubes to replace them. What is confusing me is they are only 18Wat bulbs but they are each 10000k output! I thought you only got this sort of out put from MH lights? Anyway will these be okay for me to sucessfully keep corals? I dont think I can really have MH lights as I cant have the top of my tnk open to suspend them as I have a cat and I dont want them heating up water or smashing if they get splashed plus they are expensive and I dont really know if there is room in the hood to accomodate them.
Will the lighting I have be ok?
(I want mainly soft corals, and maybe an anenome or two, but I want them to have enough light to grow, not just enough to survive)

 

[stephenray75]

You coral selection will be limited to low light corals. you should look at the watts more than the Ks. Their are other alternatives than mhs that are reasonable priced. T-5s or compact pcs. on my 20L i use JEBO 110watt compact pcs. Check out superfishstore.com i got my pcs from there for cheap. You NO (normal output) flourescents arent good. IMO you would only be able to get by with mushrooms under that light.

 

[mogurnda]

What is the size and proportions of your tank? Normal output fluorescents like yours really won't work for many corals. Maybe mushrooms and very few species of softies IF the tank is shallow. Otherwise, you might look into compact fluorescent (aka PC), T5 or VHO fluorescent if you don't want metal halides.

The intensity (for which wattage is a rough measure) and the color temperature (10000 K) are two very different measures. The color temperature indicates the spectral distribution of the light output, with low K values being more red/warm, and high values being more pure white, shading to blue. Manufacturers can provide almost any K value they want, depending on the phosphors they use in the lamps. Your 10000K lamps will provide a spectrum that will give the tank the appropriate look for a reef tank, and the spectrum will be roughly appropriate for corals, but the intensity will probably be too low.

 

[Cat]

Okay I follow.
I have spent the last couple of days going round to different Marine stores and asking loads of questions and Im starting spending next week and getting everything set up.
Now Im not going to have hard corels or clams as they are very expensive and I want to start with easier things that are hardy and cost less money in case I mess up!
So in the case of lighting I can always up grade later, I just want enough for my softys to be happy and grow a little. My tank is 18" deep, its hard to give measurements for the rest as its a corner tank with a curved front, but it holds about 50 US gal. so what wattage should I aim for?
Also does it all need to come from the same bulb or two, or can I have several smaller wattage bulbs that add up to the correct wattage?