I have a 10-gallon highland tank set up with two N. hamata, one N. x Judith Finn, and one N. spathulata x spectabilis. *Lighting and humidity are adequate...as is the soil mixture. *A frozen (2 Liter) bottle of water is used for cooling and drops evening temps to approx. 55 degrees. *The temp is 80-85 during the day.
For some odd reason, the lids on the hamatas drop over the pitcher openings....only at night however. *By mid day, they are back up again. *I spray the plants down when the lights go out, and I use a plate glass lid as a cover...so humidity shouldn't be a problem...as a matter of fact, the leaves still have water droplets on them in the morning. *I've tried leaving the terrarium cover slightly open, as well as cooling only to 60 degrees...the lids still drop...on some pitchers more than others. *
Other than this, the plants seem to be doing fine...growing tips are growing and one plant has even begun to to create a pitcher while in my care (Approx. 3 weeks). *
Any ideas as to what could be causing this? *I'd assume it's due to stress...but why do the lids close only during the evening? *Is evening air circulation to circulate the cool air a must for highlands? *Any thoughts would be greatly appreciated. *Thank you!