I never had any experience with "coco peat", but that sounds like a water-retentive mix (assuming "Compo sana zitruspflanzenerde" is actually compost). Or did you mean 1/3 pine bark chips?

-Tom

I think here it's called coconut coir and it's replacing peat in a lot of applications. I think as a replacement for peat in a container mix it can be a good option. It's higher in water retention but has a lower pH than peat. I think it also breaks down slower. The higher water retention may mean using less of it and more pine bark chips perhaps.

Here's an article on it. http://www.finegardening.com/getting-coir-matter