Natural moss has an acid ph hindering many types of spores, however not all, I use a very mild solution of Physan to stop any spores or bateria on the stems or in the water. One result is that the bacteria which normally breakdown plant matter can't thrive and the dead sphagnum moss accumulates, eventually forming peat. The acidity of sphagnum moss inhibits most bacterial growth and was used during World War One as a wound dressing, and sphagnum moss workers today report relief from such symptoms as warts, tinea and even skin cancer! Sphagnum moss has a high cation exchange capacity (which is the reason why it is used extensively in plant propagation either as sphagnum moss or in its decomposed peat moss state) which is to say that sphagnum moss has the ability to transfer nutrients extremely well; due predominantly to unesterified polyuronic acid molecules. By exchanging nutrient cations such as calcium magnesium, potassium, and sodium for hydrogen ions, sphagnum moss lowers the pH of its surrounding soil