Plumbing Advice for Sump Build This Weekend

There's normally a diatom bloom when you add fresh plastic to the tank. I don't know why that would have messed with your urchin and others, though. I added a refugium a few weeks ago (that's my only sump), and no problems from the actual addition.

 

It's really confusing...

I did notice that there was a small ammonia spike after installing the sump. I'm not sure if I stirred up the sandbed, or what caused it. It didn't last for very long, but I'm thinking maybe that killed the urchin. All of my other inverts are acting normal, though. Plus, its been a few days since the spike, and my fish still aren't acting completely normal.

 

I also noticed quite a bit of corraline die off