Hempy buckets: pH according to runoff, or don't bother?

I'm almost done with my first grow, and as you can guess it's a hempy. However, it's about 4 weeks into 12/12 and I'm not impressed with the bud size (it's C99, 7-8 weeks flowering). I'm running straight perlite, and since day one I've been checking the runoff pH and adjusting my feed to try to get it between 5.5-6.0. But...the pH has been unpredictable throughout the grow. During veg, the pH would rise in the runoff by about 1.0. When I switched to flowering, the pH was suddenly dropping by about 1.5. Now, the pH is almost the same as what I'm putting into the bucket. Crazy unexplainable shit.

I'm tired of chasing the pH around and wondering if I'm doing the wrong thing. I've done a bit of searching, and I seem to find folks saying both things: check the runoff and pH according to it, or don't bother even checking it, put 6.2 in the bucket, and just watch the plant's health.

Anyone have their own opinions/experiences with this to help a brother out?

Also, I'm really hoping it's the latter because this seems like a lot of extra work and I heard hempies were supposed to be really easy.

I don't a ph tester or ec/ppm
I give straight tap water right out the faucet(adjusting the temps with the hot side and going by feel)
I prefer to feed and do everything according to plant responses. If you start to see signs of high ph in the plant by those nutes getting locked then lower the ph of your water slightly.
I feed every watering at a lower ratio and that's it.no checking ph no adding anything extra. Your nutes may not work that simply and you might have to raise or lower ph of the water slightly along with feeding every watering or however you wanna do. My point though is to just read the plant, its no big deal... my ph might swing but my plants aren't showing signs so I carry on with my easy style of growing