ph up & down for humboldt nutrients??

im currenlty going to be using the humboldt nutrients line up and they seam to not make any ph or ph down and i was wondering if i should use a specific brand of ph down and up or if i can use any ph up or down? still new to this line up running the 3 part with some additives

Any ph up or down would work

Here:

http://www.hollandindustry.com/nutrients-additives-advanced-nutrients-litre-p-728.html
http://www.hollandindustry.com/nutrients-additives-advanced-nutrients-down-litre-p-724.html

I use Humboldt Nutes (not that it matters and I am thinking of switching to jacks)

I use this

Buy potassium hydroxide flakes for pH up.

Don't eat them. Don't rub them in your eyes. Wash your hands, etc.

Thanks guys gal? !