Your spider plant doesn't look bad at all. Do you fertilize your spider plants? This could be the problem. Sometimes if you fertilize too often salts will form in the soil turning the tips and edges of the plant brown. If you fertilize discontinue for a month or two, water the plant thoroughly during this time until the water runs out the bottom. This will flush the salts out of the soil if there are any present. Another thing to consider is...are you watering with softened water? This too can cause salt build up in the soil. You can also try adding some epsom salt to your watering regimen. This will provide the extra magnesium to the soil that plants need to form chlorophyll. And just in case you ask..epsom salts are not a salt that is detrimental to plants. I have grown spider plants for years and have never had a spider plant that didn't get brown tips on the leaves at some point. You can also try transplanting them into a different pot with new soil. Sometimes hard water deposits/salts build up inside a pot that can cause leaf browning. Are they getting enough sun? I always use to put mine outside in the summer. They need some pretty strong sunlight to stay healthy.
