removing rocks

I removed some rock from my Fluval Evo 13.5 to scrape off some pulsing xenia and then three days later my hectors' goby is dead. Did I do something wrong that contributed to his death, or was it just a fluke? Here's how it went: I removed the xenia with a razor blade, rinsed the rock off with...

So I have had my tank set up for about 8 weeks, I used live rock and media from someone who broke down their tank and added in a large piece of eco reef. I removed one of the live rock a few days in to setting up as it was covered in aiptasia. The other rock is still in my tank but I’m thinking...