I mix 10 gallons and with the air stone in it drops.what fertilizer? Using GH trio cal Mg and some B52 from AN.
I'd get rid of the B52. Essentially how much of a rise are you seeing? You should see a large rise 24 hours after mixing after that you should see a slow rise over the life of the reservoir. You never mentioned how you're growing, just blumats so I'm assuming it's coco or possibly soil
If coco make sure your reservoir measures 5.6 after 24 hours of sitting after mixing and unless you're getting wild swings you should be fine. You're not going to get massive issues if they are short a couple days from pH lockout. With soil I'd take it to 5.8 the day after for the 5 days but I'm less sure since I grow solely hydro. Again a couple days of lockout is no big deal
It's always best to aerate your water, stagnant water isn't great. Air stones are ok but mixing pumps and waterfalls are better.
Best of luck.