coldwater tank

This initial post is going to be a bit long, since I am compiling steps that have taken place already. The beginnings of this tank came from collecting local specimens, and right now we have depth of 0' to 10' for the sake of convenience. I use a dry suit to go in the 50F water, no tank, just...

I have recently discovered black sand (on this forum) and I would like to change the coral chips in my cold water tank to black sand. The colours would be amazing. However after researching the internet I have been hit with conflicting information. Some say it's good for Goldfish and some say it...