As far as bulb color to go with, since you dont have supplements, would be 20k. Its a crisper bluer light that will bring out the best colors. To get a feel for what you really want, check out some tanks that are running similar colors. I love the 20k but others may think that its too blue. I also like the 14k but it doesnt bring out the colors as well. I guess it all depends on what you like to look at.