The juwel warm lite with a kelvin rating of 2900 creates a lovely warm and natural effect in your juwel aquariumr for best results combine with a juwel day lite tube place the day lite tube at the back of your aquarium to promote plant growth and the colour or warm lite tube at the front of the aquarium to enhance fish coloursr these t8 1 thick flourescent tubes are suitable for juwel aquariums with t8 light units