OK, bought my new male today, have setup in a new 7G tank by himself, and a fluval 1+ low level filter. He was in the tank an hour when I went to check on him, and he'd wedged himself between the filter and the tank edge!!
I removed the filter, but he seems to have silver patches below his eyes, where I presume he has scrapped some scales/skin off.
Help! What should I do please?!!

I would need a picture to see if he has lost scales; it is possible that is simply exhibiting a stressed coloration. The best you can do is keep him warm and relaxed with a good amount of cover for hiding in case he is stressed out. That aside, adding a medicinal amount of Aquarium salt will speed the recovery of any scale damage, and will help stave off infection. Good luck, and do keep us posted on his progress.

Thanks, I'll see if I can get a picture up. I've had the curtains closed in there since he was put in, and added some stresscoat.