Cathy, what kind of potting soil are your sansevierias planted in? And how often are you watering? They don't look 'stretched' so I'm assuming they're getting enough light. My guess is that they're being kept too dry, or possibly too wet and the roots are rotting.

Need more info to help you, but for now I would put them in an inch or two of water until we can get your issues figured out.

Russ

Yes a photo of your soil mix, and the pot they are in would help a lot! Thre is no right scheduled watering (e.g. every 8 days) as it depends on so much.........how big the plant is compared to the pot.....clay vs. plastic...........gritty soil vs. organic soil............how warm the temps........how bright sunlight.......etc.. However as Russ mentioned those plants have very little root which could be from over or underwatering. Also old potting mix with too much salt build up could burn roots. Hard to say from the photo.

I'll send a photo later as I'm at work right now but I changed all of my sans to cactus soil when I received my new sans from you this summer. I repotted them. This one is the only one I left inside the house. I just water when I see that they are getting dry. Maybe I'm not watering enough. More photos later to show you the rest.

Okay Cathy. I assume this particular sans is in the cactus soil. Some folks find commercial cactus mix still too moisture retentive and add an equal part of perlite with it. But if you're under-watering, obviously the mix isn't the problem.

Russ