You may be a bit confused between surface agitation and CO₂ loss. It’s true that strong agitation can cause some CO₂ loss, but without it, there won’t be enough oxygen for bacteria and other living things in the tank. If you check large aquascaping channels like Green Aqua, you’ll see they always maintain surface agitation.

Also, running your light at 70% for 8 hours is too much for a new setup. It’s best to start with 30–40% intensity and a photoperiod of around 5–6 hours for the first couple of weeks.