As others have said, watts/gallon is such an oversimplified guideline that it is practically useless. What we are actually looking for is the amount of photosynthetic radiation, which you will see referred to as PAR, at the point where the coral is located.

Generally the higher the color temperature of the bulbs used, the less PAR they put out. So 5500K has more PAR than 10000K and 10000K has more than actinics, etc. So yes it matters.

so Ron101 what you are saying that a 2-5500K bulb would be better in my situation?
I am retired and have limited funds to work with so am trying to set up a 'Nano' system using what I have at hand cause to install a Halide would be ((amongst othere factors (suspending, fixture)my wife etc )) out of the question.
Frustrated in Surrey!
Jim

Well 'better' is subjective... 5500K (actually 6700K - I dont think there are 5500K PC's) would probably give more PAR but the light would look fairly yellow. Not many people find that appealing. Personally, using all 10000k is about as white/yellow as I would want to go.

However for budget reasons, I wouldnt get into buying new PC lamps to experiment. Try out what you have with some lower light corals placed higher up in the tank and maybe start budgeting for MH down the road. People often sell single MH pendants in the classifieds for reasonable prices. Just my $.02.

I would recommend Metal Halide for ricordia. They just seem to do much much better in bright light. I would move the yuma as high up in the tank as possible and see how it does.

Otherwise your light setup should be fine for mushrooms and leathers.