Wow, the ph actually is remaining stable...not rising fast like it was before. I had a funky smell in my last rez, def some bacteria action going on. I wonder if that was what was rising up the ph so quick. After I emptied it and sterilized, I made sure the buckets were light proof, and that seems to have fixed it fully.
So that's good news, so far. It's been like 6+ hours and the ph hasn't gone up even a bit. Last time, in 6 hours, it was up 3 or 4 points.
I put it low anyway, around 5.2 because i thought it would rise up fast. I'm going to check again tonight. If it's still 5.2, I'll add some fresh water to raise it up towards 5.8