QT crash

Had a heart attack this morning. Went to check the ammonia in the QT as I did every second day, and it was through the roof. Did an immediate 75% water change w/ Prime and Stability, and the pleco, who’d been just hovering on the bottom immediately picked up a bit, but ammo was still not in any comfortable range. I did small 1 quart water changes every fifteen minutes for a few hours, w/out bringing it down any further.
Around 4p.m. I finally gave up on it, netted the pleco, checked him over for any signs of burns, but didn’t see any, and moved him into the main tank.