BioFlow 3.0?

Good evening, which of the additional filter media (Phorax, Amonax, Cirax, and Carbax) make sense? I've read that the activated carbon filter (Carbax) is useful if medications are added to the water, but otherwise it can be omitted. Thanks in advance 🙂

Filter?

hi guys, I bought the Eden 511 and connected it to my 60l aquarium yesterday. Before that I had an internal filter and everything was fine. Three fish died overnight and the water is cloudy yellow. Why is this and what should I do now?