Leaves

What medium do you have it in? What is the temperature range? And have you been fertilising?

No fertilizing. I live in Florida so the lowest it will get is around 35 during winter and the highest is around 100 during summer. An average day is usually 70-90 here. And then a 10 degree drop in temperature during night. There's a lot of humidity. Always above 60. Today was 80%. I have it growing in sphagnum. I water it with rain water when the medium is a little dry almost like a wrung out sponge. Sometimes the rain water is green but I water it anyway since I don't want to use tap water.

You seem to be doing all the right things so it's a bit of a puzzle. I can't imagine a bit of algae in the water affecting it badly. What are you collecting your rain water off, and what are you storing it in? Is there a possibility of some chemicals being leached into the water?

There's lots of different species of Nepenthes around these days (being sold that is), not to mention all the hybrids. Some of them only tolerate a very small temperature range. Do you know which species it is, or hybrid? It could be that it's outside its 'comfort zone'.

The rain water is being collected from a gutter. It is possible that the water may have been too dirty. Unfortunately, the plant did not come with identification information, so that's all I can say. Do you think this could be the result of some sort of fungus? And if so, what should I do?

Rain water is fine from the gutter. ALWAYS keep the soil moist, never let it get dry. Bright, indirect Sun (BRIGHT shade) is best.

are you pouring the water on top of the plant? like, getting it all over the leaves? Maybe too much water? And oof i have had some dirtyyy water come off a roof. Have you ever let the water sit a bit and see how much sediment sinks to the bottom?

And how long have you had it? Mine lost all it's pitchers when i bought it and took it home.

An easy way to test the water is to buy a TDS meter ($15 or so on Amazon). The lower the reading the better the water. You want it below 50ppm.

There's very little sediment in the water. It is mostly clear. I never water the leaves. I mist them however with rain water to help give extra humidity. Water does not sit in the medium. I was wondering if this might be the result of dramatic temperature changes or the fact that the plant almost never catches bugs. I have it on my porch and there are barely any insects. The temperature also went from around 80 to 50 in one night.

Oh, and I've had it for 2 years now. It has been like this as long as I have purchased it. But now it is especially worse. I just had an additional 2 pitchers turn brown since I posted this.

Misting does nothing for plants. It evaporates too fast to be of help for humidity purposes. Also, the plant doesn't NEED bugs to do well. Light is more important. 50F. is a bit chilly for them.

They really should be called "semi-carnivorous" and not carnivorous. I know of plants that are saprophytic and don't photosynthesise. But don't know of any plant that's purely carnivorous.

OK so does anyone have any idea what I should do?

You seem to have ticked off the right boxes for growing it. So that brings me back to the earlier suggestion that it might be outside its comfort zone. Averages don't mean a lot with these plants. It's the extremes that bring on stress and those are the stats that you need to take notice of.