Best way to raise ph. Growing in coco

Growing in coco and my runoff ph has been really low. 5.0 around. I’ve ran water through at 10.0 and the runoff barely goes up at all. Any suggestions?

Firstly what is your ph meter?

Hanna ph meter

Ensure that your meter is calibrated properly!

What are ppms as well depending on nutes coco tends to hold on to salts from bottled nutes and in my experience it can tank the PH, also if your coco gets to dry often that can also tank your ph and become a pain to reset… I’ve dealt with both issues and spend many hours flushing much more than 3X the pot… coco is a lot like hydro when facing issues you should be seeing problems or stress with your plant pretty soon if not already unlike soil where root issues can take a week or 2 for you to see any issues coming about

It is calibrated correctly and I clean after every use. Idk my ppms. I ordered a pen and it arrived broken. The plants look good. There’s a couple leaf issues but hopefully they get corrected with the proper ph. I ran out of ph up yesterday trying to up the ph. Went through a small bottle and it was still low.