Ok so I have a 20 gallon terrarium set up, and it is mainly for highland Nepenthes. I currently have a N. Ventricosa, N. Sanguina., and a N. Maxima cutting inside. However, my question is how do I make my terrarium warmer??!!? I only have one double light fixture with a 5000k and a soft white or warm white or whatever it is called that is around 3200k I believe, but this seems to be plenty of light for my Nep's because they are coloring up very nicely. Unfortunately, during the day my high temp is only around 70 degrees and at night it gets down to 60 (which I like). Now I'm pretty sure that my Neps would like a higher day time temp than this, but my lights do not heat it up past 70 degrees, so how should I raise the temperature? Any thoughts?