Generally, if the wattage is not too bright, you can use 1 watt spotlights for fish tanks below 40cm. Generally, there are two styles, one is a clip, that is, it is convenient to change the position when using the clip, and the other is a knob, which is firmly fixed.

There are more fish friends who choose the knob. Choose 3W for fish tanks above 40cm and below 60cm, 5W for fish tanks from 60cm to 120cm and 7W for fish tanks from 120cm to 150cm. Choose according to the table below.