I also adjusted the height of the upsteens on two of my grow beds. The water level just wasn't reaching the roots, and upon inspection, I realized the level was well below the recommended 5cm depth (from gravel level down). The plants in the bath tub were fine, as the water level there was reaching about 5 cm below the top of the gravel.
My PH level got back up to 8. It must have something to do with the gravel. I squeezed one lemon into the system and will add one per day until the level gets below 7. The high PH shouldn't hurt the fish, but it definitely won't be good for the plants. This will all be academic once the system stabilizes, but for now, I'll just have to keep an eye on it.