This the first cactus I've ever had. It is only a couple weeks old but the top parts of it are shrinking and browning (they browned during the night, to be precise). I don't know what it's happening... I watered a little bit the soil 4 or 5 days ago with a water sprayer. I kept it on my desk for a bit and I've being putting it out of the window from 8am to 5pm every day since this Monday. It has direct sunlight from midday to 4pm (a friend of mine told me too put it under direct sunlight for a few hours a day, but I'm not sure it is a good idea).
I'm pretty sure I'm doing something wrong, but I don't know what because I've no experience. However I really would like to save this plant beacause it's a gift I received from a person really special to me.
So, I would like some suggestions about:
1) where to keep it (I would like to keep it on my desk even if there are no windows);
2) how much light and water it needs;
3) what to do when it will get cold outside and there will be no sunlight (I live in a Northen Italy area that's very humid and rainy all year long);
4) whether I should cut or not the top brown parts of my cactus;
Thanks in advance for your help
