When I checked the plants the other day, though, I was horrified to see that the leaves were wilting.
I realized what had happened. The plants had grown so fast that they sucked the water all up, until it was bone dry. And it all happened so fast the "Water Low" indicator didn't even have time to light up.
I quickly filled the basin with water, but it seems the damage had been done. On two of the plants, the leaves had already wilted past the point of being salvagable. Strangely, the other two plants were doing just fine. My guess is that these two plants had sucked all the water for themselves, leaving their brethren parched.
I plucked all the dead leaves off, but I noticed that there were still tiny little leaf growths on a few of the joints of the branches trying their best to pop up. So I gave the plants a huge pruning, cutting off the branches with the dead and dying leaves. This left me with a couple sticks:
I poured all the water out and refreshed it with clean, warm water and fresh nutrients. The lesson learned, of course, is not to rely on the low water indicator, and to remember the check the water daily when the plants start getting big. I also noticed that the airstone wasn't really aerating the water very well, so I replaced that too.
We'll see if the little guys have some resilience after almost dying of thirst!
