High-Lite refers to the new light technology by Juwel Aquarium. It combines the existing tube lengths of the T8 with the new bright T5 technology. High-Lite Colour tube enhances natural colours with a colour temperature of 6800 Kelvin . It intensifies red and blue colours. For Freshwater we recommend following combinations: Colour + Day The 438 mm / 24 Watt High-Lite Tube can be used in a 55 cm or 60 cm light unit. The following aquariums can be fitted with this Tube: Trigon 350, Lido 120 High-Lite Tube Colour 24 W (438 mm) High-Lite® refers to the new light technology by Juwel® Aquarium, an improved lighting version on the old style T8 standard bulbs It combines the existing tube lengths of the T8 with the new bright T5 technology. The Juwel High-Lite Colour creates a stimulating red light in your aquarium. The specific High-Lite Colour spectrum is perfect for highlighting the many red and blue tones of your fish and plants. • Perfectly highlights red and blue tones • Ideal for use in conjunction with JUWEL High-Lite Day Juwel Trigon 350 Juwel Lido 120 Warehouse Aquatics Recommends Over time \"cathode decay\" causes less energy to be transferred through the mercury vapor in your tube. The main effect is that the tube will emit less and less light as it gets older. It happens slowly so it\'s difficult to notice unless you put a brand new tube alongside an older tube, but the light output will slowly dim until it suddenly stops dead one day and this can take years. You might think manufacturers recommend replacing their tubes every 6 months to keep you buying but there is a lot of truth in this. A tube emitting less light although not entirely noticeable to the naked eye is extremely noticeable to your plants to the point where after 6 months you may find the only thing you can grow well is algae! So for the sake of your plants the WA Team recommends replacing your tubes every 6 months or at least every year, a little tip of writing the installation date on your tube with permanent magic marker will help you keep on top of this. For the sake of your wallet we recommend replacing your end caps when you replace your tubes. The caps prevent water getting into your light unit, if this happens it will be the end of the road for your light unit and this type of water damage isn\'t covered under warranty. The caps have a rubber gasket which prevents water ingress but over time this rubber degrades and becomes brittle when exposed to the lighting emitted from your bulbs. It means that the end caps loose the ability to prevent any condensation getting into your unit. At a cost of around £4.50 for a pair of end caps vs the cost of a replacement light unit (starting from £65!!!) we can\'t recommend replacing your end caps enough. Please see the related products tab above this description for all the accessories related to this tube.