Just to clarify: Lumen does not refer to "total light output", although it implies that it does. Lumen means the brightness of the bulb to our eyes. Our eyes are more sensitive to greens than blues or reds, photosynthetic requirements are the opposite. Lumen is still a vague indication of brightness, but you can have a plant bulb with very low lumen output, terrible K rating (in the 6500K 'ideal' respect), aweful colour (purpleish), but be exactly what the plant is looking for.
Similarly, a true daylight bulb will have lower lumens than a more green bulb of the same power.
What you've got is a 25W compact fluo. screw in. From your description, it sounds like the 'soft white' variety. Those bulbs always make the point of saying equivalent to X Watts, but it's a marketing thing. What they mean is that it's as bright as an incandecent bulb of that many watts. Otherwise people who've grown accustomed to their 60W bulbs would never buy the "energy saver" rated at 15W, they'd think it too dim. But this has nothing to do with the watts per gallon that is often quoted for aquaria.
