I agree that i wouldn't dose either. A few common practices are room aeration, fresh air injection through skimmer, co2 scrubbing, 24/7 refugium, using kalk in top off water, using two part instead of calcium rector etc
What you can do (or want to/need to do) really depends on your setup. Where is the tank located? Volume? Skimmer or not? Granted 7.8 is a little on the low side but as mentioned you night not want to do anything drastic. Give us a few more details and I'm sure someone will chime in...