Oof, dude. Your still way over complicating things.
Your "2000w" LED probably isn't actually 2000w, and it's definitely not "optimal" lighting if it has a bloom and veg switch. I'm guessing it's a blurple. Run both switches on at all stages, it's just a gimmick to be able to switch some of the spectrum on and off.
Co2 is for people with completely sealed grow rooms cranking 50w+/sq ft. And I mean true watts, not what the "equivalent watts" listed on cheap Chinese LEDs from Amazon.
Don't use fertilizer to get your pH down, buy some pH down. I've heard you can use lemon juice or vinegar to drop your pH but I've never tried it.