Okay, about a month later and I've still got the 55 with the cracked trim laying around. I'd rather use it than get rid of it since I did get a sweet deal initially with this tank...
Would I be able to fill it half way(or less than that)?
I should think that with only half the tank filled, the strain on the glass would be significantly less so that the trim would be a non-issue. I'm thinking something like this riparium that Hydrophyte made over on The Planted Tank