I have a 10 gallon tank I am currently cycling. There are no fish in it and it does not have a light. I keep the temp at 74ish and run a small sponge filter with an airstone. About a week ago I noticed some debris when I stirred up the substrate while adding a fake plant. The substrate is just cheap colored gravel from a BBS. I was out of town for a few days and came home to find a few beige blobs floating on the surface. It has the texture of a loose paste, no discernable smell. It's also in the substrate and all over the plant and the hardscape. Also, it's gross!
Any ideas?