ok, i take it your a little new to hydroponics correct? instead of experimenting why dont we try something we know works, for one even though you check your ph daily and make needed adjustments, when i say you want a stable ph, i mean that your nutrients can hold that neutral ph balance for weeks at a time without having to make daily adjustments, since your doing a bubble system any ph change is going to effect the root immediatley, also i wouldnt recommend using vinegar and baking soda, they dont work to well and vinegar will make your nutes nasty and baking soda will make them thick like beef stew, stick with a simple ph up and down from the hydro store

you also said you would be purchasing a ppm meter, if your budget is tight go with a ph meter instead because the test strips suck and ppm isnt going to make a differance anyways if your ph is off balance and your plants are going deficiant, just do biweekly water changes and just top off with water ass needed

now lets find a nutrient that is going to work and be very simple for you, if you can get ahold of a sensi pro pack, they got one for veg and one for flower, take it and run, those things are fool proof they even balance out there own ph for you, if you cant you can always try the flora series from general hydroponics, they usually come with some easy instructions, try to get ahold of the manual it has some awesome feeding schedules to go by that make it very simple, you also can try what im currently using, pure blend pro from botanicare, its a simple 2 part nutrient solution, 1 for veg and 1 for flower, its completely organic and works very well if you ask me, i also add liquid karma to the mix which has micro nutrients that help develop a strong root system to better absorb nutrients, then i throw in some silica blast which i recommend to any indoor grower, this stuff helps the plant fight back against harsh conditions such as high temps and high humidity and other stress of that nature, it also promotes fuller more lush growth

i use them in this order, 1500ppm(1300 pure blend pro, 100 liquid karma, 100 silica blast, when i go to flower i raise the pure blend to 1500 ppm and keep everything else the same at 100)
since your doing a bubble you may wanna go a little weaker since your nutes are always sitting in solution, i might try 800ppm for pure blend pro and keep liquid karma and silica at 100 ppm each, some might agree or disagree i have always been an aggressive feeder, the key here is to keep it as simple as possible my friend while finding what works best for your situation, theres so many advertisements out there you gotta read between the lines, i steer away from products that promise a little to much