I read somewhere today an explanation about upgrading tank lights, saying that simply adding bulbs is not the best solution.
They stated that you should always get lights with the highest wattage, rather than doubling up on lower watt bulbs.
For example, if you had two 20 watt bulbs, the total wattage is 40 watts, but the intensity is still only 20 watts, while a 40 watt bulb has the same output power, but at greater "lumens" (if this is the correct term).
They further suggest to take this theory to the limit and go out and buy compact florescent bulbs at 30-50 watts or so and just throw a couple of those in rather than building complex setups for adding multiple long tubes. The end result, they say, is many watts at great intensity without spending a lot of money or time to set up. (I don't even know if you can buy compact light bulbs that specify temp)
Sounds right on paper, I guess, but I was wondering if anyone here had heard of this....