I just started a 10 gal terrarium, 40 W fluorescent, sealed except for a crack in the lid, 80% humidity, 80 temp. I have 2" of clay pellets on the bottom, covered by nylon, then a 50/50 mixture cocofiber/tree bark originally soaked in a small amount of DynaGro fertilizer added to the 1 1/2 gallons of water used to soak the coco fiber. There is a 1/2 inch standing r/o water in the pellet layer and the substrate is moist and not soaking wet. I have a Pilea and a Selaginella K. growing. They did fine for about 3 weeks, and then the Pilea began to loose leaves which turned brown/grey. The Selaginella K. started to lose its green color and just dry up. At the time I noticed that there was no more water in the bottom of the pellet layer so I added 1/2 inch and misted the substrate. Now my Pilea is sending out a whole bunch of new small leaves. The Selaginella doesnt really look any better.
Help. I dont know what is up. Did I put too much fertilizer in the initial water? My tank always has nice condensation on the sides even when there is no water in the pellet layer. I think my lighting is good and so are the other parameters. I even tried opening the lid a bit to lessen the condensation on the sides with no real improvement. I dont think it is light, water, humidity or temp? So what is wrong??
My terrarium still looks lousy so I did some exploratory surgery on the roots. The plant roots on the Selaginella are still light tan and some light tips. The Pilea is also has good roots, no rotting.