Add LED to existing water pump
Question
How to DIY a waterproof LED lamp?

Answer
There are expensive water proof lamps, but if you are a poor hobbyist like me, and have minimum DIY skills, you can buy a cheap, low voltage (DC 5V) low power (0.2W), USB LED lamp (Ref 1 below), and make it &quot;waterproof&quot;, using perhaps heat shrink tube or similar goodies.
Or if you are poor and lazy like me, you can just do the following:






No Guarantees
1. No guarantee it won't work for too many years.
2. No guarantee it won't melt down, blow up, or electrocute your fish.

References
(1) AliExpress USB LED Lamp Night Lamp