How much water are you giving it? They grow best if you SOAK the pot - submerge it in a bucket until the bubbles stop coming up, then drain it - and then let it dry out almost completely. Use a moisture meter ($10 or less in a gardening section at any big supermarket or home store) and not the calendar to control the watering.

How much light are you giving it? They can survive without direct sun, but they do need quite a bit of indirect light, such as from a north window.

for water, i use a spray and give about 10 sprays until leaves and soil are wet, then water again in about 1 week's time.

for sunlight, it is facing sun but i have to pull the curtain (sunlight proof) open every morning, sometimes I do forget to open the curtain so the pot stays in darkness whole day.

I would post to the sans forum and see if you get any other additional clues to what's going on.

I have a bird's nest hahnii (Sansevieria trifasciata) that I have potted up in an open mix. The thing pups like crazy and I can't seem to do anything to keep it from doing it's thing. I've had it for about 3 years now and my interest in it waxes and wanes.

I think it surprises me that it's not just still hanging on, but doing well, despite the lack of attention that by contrast, I lavish on my jades and other newest obsessions. In short, it's the LEAST fussy plant I own.

I don't know if the mix is the difference between mine and yours, but I expect they have the similar needs.

I keep mine in indirect light, water once a week or so with weak solution of fert, when I remember to water.

good luck with it & DO post an update =)

Underwatering can be just as detrimental as overwatering. Underwatering and not watering are two different things. I have barely watered mine since bringing it back indoors for the winter, and it hasn't phased it one bit. But when you underwater a plant, then you run the risk of the minute traces of minerals in the water slowly building in the soil up over time, making it more difficult for any plant to efficiently absorb water.

Instead of just spraying your plant, I would follow LazyGardens suggestion and thoroughly water your plant and then let it dry out before watering it again. And it's not necessary to water the leaves either, given their somewhat waxy texture. They don't really absorb water water that way. This may be why you're having leaf problems.

Spraying isn't watering. It's the growing medium that needs the water, not the top of the plant. The mix looks very dry and peaty. Are you sure it is getting properly wet? As lazygardens said you need to soak the mix then leave it alone until it needs watering again. Don't stick to a timetable as the amount of watering varies depending on conditions.

Forget spraying! They need watering. Water the pot until water comes out of the bottom of the pot. They don't need much water. About every two weeks.

The growing medium it is currently is in horrible. Get it into a faster draining mix like cactus mix amended with perlite (cheapest and easiest for most to do). Mix at at least 50/50 or go heavier on the perlite. You could even mix in some gravel to make the mix grittier.

I agree with the others. Your watering regime is ineffectual. Water until you see it coming out the drain holes in the pot and then leave the plant alone. In winter, watering once a month is enough and may even be too much. Skip the moisture meter....a waste of money and you can do the same thing with a pencil/skewer/your finger....like poking a pan of brownies with a toothpick. If there is soil medium stuck to it, you don't need to water.
Light is not really an issue here. These plants can live in shade for months and not be bothered.

What I think is happening is that the mix in the pot has dried to an almost concrete consistency around the roots of the plant. Your watering isn't doing anything because all it is getting wet is the top of the mix. I suspect that even if you watered like normal, the water would not penetrate the "concrete". So, essentially, the roots of the plant aren't getting enough moisture, if any at all, and the plant is using up it's stored reserves and slowly dieing. Any water you give it is running along the outside of the mix and finding the path of least resistance to the drain holes.

Agree with the above and you have two issues there. The soil (and roots) are not getting moisture. Also wetting the leaves, esp. in winter can be bad. those two larger leaves in the photo have rot going on and it is probably doomed. I also agree with the above in that the soil mix shown is bad. At this point I would probably start over with a new plant and plant it in better soil and follow the advice above.

Your plant is growing in PEAT MOSS. Terrible soil...especially for a succulent. Although most people just seem to focus on the potential wetness of peat, they ignore its opposite problem. Once they DO dry out, it is almost impossible to remoisten the mix. Your plant needs H2O!

Snake plants don't like a lot of water. Also, when did you change out the soil last?