[trenac]

Paul, do you know that Coralife now has a 30" freshwater fixture available. I would also opt for the 65 watt fixture for a 20G long. I have a JBJ 30" 65 watt fixture on my 20G long and it gives plenty of coverage all the way around. IMO, the 96 watt will be to much light for the 20G long tank since you do not have as much depth to penatrate.

 

[trenac]

The K rating 5500-10000k all benifit plant growth, its the actinic blue bulbs that are used in marine setups for coral growth; how much or little actinic blue bulbs benifit plant growth is still up for debate. The K rating you get depends on the color that you want, some mix K ratings to get the color combo they desire.

10,000k- bluish white or bluish tint

5000k- yellow tint

6700k- color tint between 10000k & 5000K