How long and what to use to change ph in soil

My ph is 4-5.
I’m using Black Gold all purpose.It’ph seems to be a low 4.5 and I need to raise the ph of 2cu feet of it.
I have ph up and down and my water is probably a high 6.5.
What can I use to change ph of soil and how long does it take for a fresh bag of potting mix?
I have a 3 gallon container full pot potting mix saturated with water this was for ph testing.If the lime is added when soil is real wet does it speed up lime changing soil’s ph?

I’m soaking soil in water then testing the drainage after 45 minutes but the water turns rusty brown from soil before I add the green ph tester.
I’ll let sample sit and maybe the dirt will settle changing color.

Is this soil you have plants in already? I prefer using a soil probe for determining your soil’s PH over the swimming pool like test drops or tablets. If there is not a plant already developing in the soil, I’d add diatomaceous earth (which is high in calcium and other minerals that would bring your PH up) or lime from your local garden supplier and thoroughly amend the soil to get a 6.0 to 6.5 PH. PH up or PH down liquid is more for adjusting your water’s PH or for hydro. I’m not sure how good it is for soil.

Maybe Latewood can chime in on this one as he has more experience with soil, I’m mostly a deep water culture guy.

After letting dirt in water in vial settle the color changed to 6.5.

If I want to buffer PH in soil; I use “Dolomitic Lime”. 3 bucks a bag at any garden center.