I came home and looked into my tank to see in the corner a buildup of bubbles no more than 1-2 centimeters thick and a spreading a few inches over the surface. I have 1 male dwarf gourami in my tank and 4 mollies, 1 hillstream loach, and 4 ghost shrimp. Today I added some drops of accu-clear into the water, could it be from that, or is it from my gourami being happy enough to start building a bubble nest? Help 