Browning leaf tips is very common in air plants, especially varieties that have wispy, delicate leaves like the T. ionantha or T. fuchsii v gracilis. This doesn’t necessarily mean that you are doing anything wrong, as it is common for slight browning to occur soon after your plants arrive in the mail. This may be a sign that your air plant is adjusting to its new environment. When plants are stressed, they may display browning leaf tips.
The T. fuchsii has wispy leaves and can have browning leaf tips if not adequately watered
There is another common culprit of brown leaf tips. Your air plant may be getting too much sun. While they do enjoy being in nice filtered sunlight, if they are in direct sun all day long, this can cause your plant to get sunburned and turn brown.
Browning leaf tips can also occur from not watering your plant enough. A common misconception about air plants is that they don’t need water or at least not much water. They are called “air” plants, but they still need to be watered weekly. Make sure to shake out excess water after watering so your plant does not rot.
Along with browning of tips, you may notice that your air plant has some browning towards its base. This is perfectly natural for many air plant species, such as the T. juncea or T. melonocrater tricolor, but if you see the base of your T. xerographica or T. ionantha browning, this may indicate sickness such as rot, or drying out from lack of water.
The base of the T. melanocrater tricolor is naturally dark
Another issue that you may notice is that your air plant’s pretty green leaves may start to turn yellow or it may be displaying brown spots on its leaves. This may be caused by too much sun, or too much/not enough nutrients. Overwatering or under watering can also be the culprit of yellow leaves. Brown spots can also be a sign of too much sun, watering issues, fertilizer burn, or even pests on your plant.
One last tip: Don’t try to rescue an ailing plant by over watering or over fertilizing it! This will only exacerbate the problem! If you do see your plant is slightly dry or browning, it is ok to soak to see if you can revive it, but don’t over do it! An ailing or dry plant should also be placed in an area where it can "rest" while still allowing for adequate light.