[Zapins]

From what I can tell the 510 tropical fish tank is roughly 20 gallons. You will need 36watts, 55w or 65w of power compact light depending on whether you want low, medium or high light.

I recommend 55w.

Kelvin is simply the color the bulb emits not how much light. Lumens are a measure of the bulb's intensity. In any case you will want either a 6,700 K or a 10,000 K bulb (more blue). 5,500 will be quite red, annoyingly so. 7,800 K bulbs are harder to find.