In general pool lamps are very simple to replace when they blow and the pool water level does not need to lowered. The light units are attached to the housing in the pool wall by a length of cable that allows the unit to be lifted out of the water and placed on the side of the pool while the bulb is being changed.
A replacement 300 watt bulb is normally priced at around €30 to €45 and fitting is less than an hour per bulb.
All pool bulbs are 12volt so there is a transformer that reduces the mains supply usually found in the pool room. On occasions these may need replacing but again this is a very simple job. Prices start at around €70 depending on the make of transformer and replacement is again less than an hours work.
​When building a pool make sure this type of lamp is installed as we have seen types used that really should not be in a swimming pool.
Modern LED lights run on around 20watts rather than 200 or 300watts of the tungsten versions so even though they are more expensive to buy the cost of running them is much less.