Thanx Guys, today I'll give it the first fill. I already cleaned it from unwanted silicon. Thats why I chose tempred glass, just beeing afraid to explode and yes, maybe I should be more careful not hitting the corners. I wonder if i can put any protection (not rims). anyway, it looks good and I am happy with it as a first DIY tank ever :-).
I would like to thank everyone in this Forum since I learned alot to give it a try.