Nobody likes to talk about their failures….except me. They are learning opportunities. My first spectacular failure was I accidentally “built-in” a razor blade into my scape. I don’t know the “why’s or how’s” of it. Because the razor blade was built into the mortar and was mostly protected, the rust took a while to start and start having an affect. Only some zoas and mushrooms survived. Hair algae was ridiculous. 3.5 years later while moving a part of my scape the scape broke and out fell the razor blade. I wasn’t even mad, I was just relieved I found answers. I lost a lot of stuff I don’t think I will try to replace but right now my reef is doing very well. My policy now is “no metal is set down where it can fall into my tank. This experience was a tough one.