Good news! The glass dancing has finally stopped! I think I can stop panicking that he's not going to make it past a week with me, because he has! I've had him 1 week and 1 day

Been keeping an eye on him all morning today, and he seems good, so providing there's no change later, I'm going to do his first salty water change tonight (eep!)
Skimmer arrived from ebay too, although I don't think it's as good as I thought it was. When I was reading the ad, it really came across as a hang-on-the-back one, but when it turned up, it's an internal one, which I'm not too happy about. But I've got it now, and fitted it, so we'll see how it does. Not that it's going to be much use in freshwater, but you know how it goes, new gadget! So have to play with it! lol