There's a lot going on in your questions.
If you're working at some warehouse that you just got hired at, then ask someone there, they will know.
If thats not the case.
PH up & PH down are definitely the least natural/ healthy/ organic, whateva the f you wanna call it, parts of using a synthetic nutrient regimen, so the less you can use of either, the better. & I definitely don't recommend using them both in one reservoir mix. example: you add too much down so you throw in some up to get it right but you went to high so you throw a little more down in<--- dont do that. But you use the right amount the first time, no big deal.
You're PH best serves you when it's consistent. if you're using soil as a medium, then yeah, 6.0 -6.3 or so is right where you wanna be. But, if this facility of yours is using a soilless medium, i.e "hydroponic" then drop that bitch to 5.8. <--- thtat's key right there. not sure if this was your question but; if you're using a hydroponic system you dont want that PH anywhere near 6.3 & or up. it's 5.8 or nathan
idk if at home you're raging some soil, and this facility is rockin dro & thats your question? but lemme know if any of that helped