Since most lights on the market for small aquariums under 20 cm have a surprisingly high light output.
Week aqua have developed Week aqua mini 9 pro a dimmable RGB lamp with UVA. It is a dedicated light for small aquariums that can be managed with a smartphone app and does not require a separate smart socket, making it a cost-effective light that does everything in one unit.

The 585lm lamp is ideal for growing aquatic plants in a small 20cm cube tank.
If used in a curved tank such as a Botrium, please use a separate magnetic plate to secure the lamp.