okay, well we seem to be headed into winter and received alot of rain lately and i just did a water change.Thing is i tested my kh today and it was at 4dh.Normally when i test it was around 8dh. with a ph of 6.8 and a kh of 4 my co2 levels are not right.Do i need to buffer my water or is 4dh okay, and just up the co2? what is the process if i need to raise my kh? thanks