The Sylvania Lux T5 are used for the promotion of plant growth, these bulbs strengthens the natural colours of plants and fish in aquariums, whilst also promoting the photosynthesis process. The lamps achieve this by using a high (but safe) level of blue and red radiation, this colour spectrum provides the optimal light colour for plants and aquaria. The Grolux range are also recommended also for use in greenhouses and indoor gardens. 24w 438mm T5 has 50% more light than T8