Thanks a lot Elaine!
You gave us many good tips. It's possible that the leaves aren't nice dark green because of the winter. I have it inside for a few months now, don't water it too much and don't remember when I fertilized it the last time. I'll try it with the horse/rabit food when it's a bit warmer and days longer. We have around 0°C during the nights and really rainy these days.
I'll watch that brown part in between the leaves and really hope it's nothing serious.... I'd love to have some peace with my Clivia now as it overcome too many troubles for one plant
(in my opinion).
... first couldn't get rid of small white bugs in the soil, then the leaves had brown spots and started to get brown, then some yellow mushroom started to grow in the soil :biggrin:.