Why is my moss turning brown???

There are several things that can cause your moss to turn brown.The water can have too much chlorine in it. It is better to use either tap water that has set for 24 hours to de chlorinate it or if outside to try to use rain water if you need to water outside moss gardens. Also not all moss varieties adjust to high humidity so they are not good candidates for closed type terrariums. Being in a closed condition causes much humidity so you can either keep that moss out of the container or open the lid and let air circulate for several hours. Also not all moss likes to be sitting in lots of water(Pillow moss) will turn brown if it stays to wet. The soil is important to...remember moss does not have roots like most plants but absorbs the nutrients in other manners...it prefers a more acidic soil and soil or water that is to alkaline can cause it to turn brown as well.