any bulb claiming to be a tri phosphor will provide you with the highest quality light, bring out the clearest red, green and blue colors.
GE Starcoat bulbs are all tri-phosphor, and so are the Sylvania Designer series. However, those bulbs are all designed to perform above water, not under it.
Even a few inches of water absorbs a LOT of red light, so aquarium bulbs make up for this reducing the green output of the bulb, so that the light viewed under water appears "white" to our eye, but above water the bulb will look blue or purple (depending on the color temp). A GE Plant and Aquarium bulb has a color temp of about 3800k, but has almost no green in it, so it looks half-way decent underwater for a cheap bulb. Simillary the Sylvania Daylight Deluxe has a color temp of 6500k, and has decent red and green spikes, with a moderately strong blue spike (giving the light a white-blue color). Something like a 10000k bulb has a small bit of red and green, as well as a huge blue spike, giving the bulb a very strong blue tint, but when viewed under salt water, the light is a nice crisp white.
If this is for a 4ft long tank... I would recommend the sylvania daylight deluxe bulbs. If you buy a 25 bulb case, the bulbs are as cheap as ~$1.50 each, and replacing the bulbs every 6 months would be cheap and easy, of course, the 2 pack for $6 is not bad either! Each bulb is 40 watts NO but easily overdriven at least 3x (I did not see any difference in brightness between 3x and 4x)
HTH
Gordon
