Question
What causes the tips of the spider plants to turn brown and start to recede up the leaf?

Answer
Denise
Usually it is caused by improper watering technique and lack of humidity...
The key to success with your spider plant will largely depend on how you water it...Plants die from too frequent waterings, not from how much water you give them at one time...Also letting them go too dry between waterings causes wilting and can cause other problems (Insects,brown tips, etc.)...
Water your plant in the following manner for greater success...
Check how much the plant weighs when thoroughly watered VS its' weight when it is ready to be watered again. Sometimes it helps to put a saucer under the pot when watering and let the plant sit in water for 10-15 minutes. Pick the pot up #or lean it if it a large pot# and feel how heavy it is after watering it thoroughly. Don't water it again until it feels considerably lighter and the top of the soil is light in color. Depending on plant types, sunlight exposure and pot size plants will need water at many different rates (1-2 times a day to once a month or more)...
Spider plants like bright indirect sunlite...Morning sun is best for them...Too much sun will cause burning of the leaves...Cut off brown tips with scissors...Spray mist the plant 2-3 times per week to keep the leaves clean and increase humidity...

Hope this helps...Let me know what you think of my advice...

Rick in southern NJ