Brown, slimy roots that smell bad usually mean root rot. The most common causes are too little oxygen and water that is too warm, often together.
How to Fix It
- Add aeration with an air pump and air stone, or improve air exposure in the system.
- Cool the reservoir and keep it covered to block light.
- Remove badly damaged roots, clean the reservoir and mix fresh solution.
Prevention
Keep the solution oxygenated, the temperature moderate and the reservoir clean. Check the roots when you check the level.
Related guide: Problems.
