Dude two days ago I did the same thing, I made a new tent and two of my lights broke. I had to replace them and now I got some rebar wire and tightened it securely. We learn. Haha. When it fell my bucket was to the side, I had a feeling so I moved it. Forgot to put a pillow. Haha. Now take that math, and have your pH at a higher lv now, try 6.5. Make sure to clean everything. Drip hole, drain, pebbles. All very well, I'm sure that's what it is. Mine actually goes up. Idk why yours goes down, so mine I mix at 5.5-6. So when it gets in the resovoir and starts flowing it will get higher. 6-6.5. Then in between I use pH down, not more than 2 ml a day, 2 ml a day of pH down = 14 ml for 7 days. I probably adjust it 3 times a week. At that. It starts good. But I used those numbers in case your pH went down everyday. Adding too much can mess you up.