will adding some sand to my substrate mess with my chemistry?
I have gravel in my tank right now. But I want to add a little sand or "Plant" substrate to my tank. I have heard of adding a new substrate completely throwing off your cycle. Isn't this true only if you completely switch out sand for gravel or vice versa? All I want to do is ADD sand/plant substrate to my gravel. I do not at all want to get rid of the gravel. Is this okay to do? Will I harm my tank at all?