Looking at some water holding capacity data, peat and Turface both hold onto similar amounts of water. I am wondering why it is peat is preferred in the 511 mix. I suspect that the ability to hold water is really only part of the issue. I suspect that peat has a better ability to release moisture back into the soil, but I don't understand what that concept is or how to quantify it. Can someone talk about what things peat does better than Turface, specific to use in the 511 mix?