I'm planning on doing my first saltwater tank soon and I'm doing research on RO/DI units. My question is I have well water that runs through a water softner out of the tap my pH is 7.0 and after it sets for 48 hour without an air stone or anything my pH rises to around 8.4 now does this show that I have high levels of co2 in my water?

) Just pour up half a gallon in a bucket - test - aerate for half an hour - test.

