[michelledryan]

I have a 46 gallon which holds a 36 inch hood(light fixture). I bought a new Marine glo 30watt bulb. The highest watt for the 36 inch hood is 30 watts. From what I have researched it states the rule of thumb is 2-3 watts per gallon in the tank. So what can I do as far as lighting? I have Red mushrooms and Green star polyps which of coarse are photosynthetic. I don't want the worries of buying a double bulb fixture that would end up raising the temp in the tank and need a fan running constantly to keep it cool. Help me please I'm stuck. What would be the cheapest but best route to go?

[msbdiving]

What will the ballast take? If you want, you can change it out if you want to put 65w bulbs in. I sliced and diced my hod to put two small fans in to keep it cool. You may also want to elevate the hood to allow for air to flow through. You will get increased evap, but top it off with fresh water and you should be fine.

[glampka]

Michelle, having only the 1 light will severely limit the kind of corals you will be able to keep. You need to decide what kind of corals you want to keep & go from there. I'm guessing that you have a glass cover on the tank. That will keep the heat in the tank. Adding a second light will not necessarily increase the temperature. Give more specifics about your tank like # of powerheads & model, pumps, etc.....

[WILLIAM1]

Ive learned that 3-5 watts per gallon is just meadium light anything lower is low light polys need at least 3-5 watts per gallon I believe. I run 4 65 watt dual daylight 10000k and 4 65 watt dual atinics 10000k with moon lights of coarse. thats almost 6 watts a gallon in my 90 gallon tank. and still am having a little harder time with some of my polyps.

[pogodzib]

The minimum lighting that you would probably want to go with would be a 2x65w or 2x96w dual PC light fixture. It is tough (although possible) to light a tank using only NO fluorescent lighting if you only want to keep the least light demanding corals. Most dual light PC fixtures already have fans built into the unit and don't heat up a tank very much. To save cost, your could go the retrofit route and install the lighting inside of a homemade hood.

BTW - Through the watts/gallon idea out the window. I think is is summed up best by mcintosh in a different post:

Originally Posted by mcintosh

I think the best way to go about the lighting issue is to break it up a bit.
High light - light loving animals throughout the tank, from the top of the tank to the bottom, clams on the bottom of the tank.
Medium light - Light loving animals at the top of the tank, lower light required species at the bottom.
Low light - Really, a softy tank. Maybe a few montis or LPS up top, and very low light animals at the bottom of the tank.

High light--
18 inch deep tank or less 150 HQI/175 MH plus supplemental lights per 2 square feet.
24 inch deep tank or less 250 W MH plus supp. lights per 2 square feet.
more than 24 inches 400W or greater per 2 square feet.

If using T-5's, as many T-5's lights as will fit across the tank (Probably need 8 T-5's spanning the full tank)

Medium Light --
18 - VHO/PC @ minimum of 6W per gallon or 70w MH/poor PAR 150/175, no supp.
24 - 150/175W MH or approx. 4 T-5's spanning the tank
>24 - 250W MH or approx 6 T-5's spanning tank

Low light --
18 - normal output Fluorescents over tank (ie 4 40W fluo. over 55 gallon tank)
24 - VHO/PC's no more than 3 or 4 watts per gallon (4 65W PC's over 90 gallon tank)
>24 - same as 24 inch tank above.

HTH. And feel free to flame me on any of the above statements. I know that there are exceptions, and I am more than happy to hear about them.