substrate turning brown?
I have some substrate i bought that is a dark gray color. I just recently took out all of the dirt, about a month and a half ago and moved the tank and put it all back in. Been running the tank for almost a month now and the gray dirt is starting to form big brown spots. If you want me to post pics later i can but has anyone ever experienced this and do you know what it is?
There are no fish in this tank and there are only a few plants.