Tumbleweed

After getting my new Apex controller I have been watching my Ph readings for the first time, and I have noticed that my Ph has a range of 7.9-8.1. I have to assume that my ph has always been around this number and just didn't know it. i have done some searching and have found many different answers to this question. Some say it should be in the 8.1-8.3 range and low readings are due to low Alk or a high carbon dioxide level in the tank/house, others say that any real level is ok as long as it stable. ...