My Taiwan Moss Just Turns Brown & the Green Parts Don't Grow

Phosphates

• High phosphate levels in the water are the most likely cause of brown leaves on Taiwan moss. It is even more likely when the moss is planted in an aquarium that also contains fish. Phosphate is commonly present in tap water and Reverse Osmosis bottled water. Decaying organic matter in the tank such as plant leaves and fish food increase phosphates to levels that are harmful to the plants and fish. Change the water and vacuum the substrate. Remove 20 percent of the water from the tank. Use an aquarium substrate vacuum or siphon to remove decaying matter from the tank floor. They are sold in aquarium supply stores.

Filtration

• Remove the water filter from the tank, throw away the old filtering material and clean the filter housing thoroughly. Filtering the water through a dirty water filter and dirty filtering material will add to already high phosphate levels. Take the filter housing and tubes apart and clean them thoroughly under running tap water. Use a bottle brush to scrub the insides of the tubes if necessary. Fresh water should be sufficient for cleaning the filter. There should be no need for the use of potentially toxic cleansers. Put the filter housing and tubes back together, insert fresh filtering material and place the filter back in the tank. Re-fill the aquarium with water that has been allowed to sit for 24 to 48 hours or water that has had the chlorine removed. Make sure the new water temperature is within a few degrees of the temperature of the water in the tank.

Temperature

• Water that is too cold will cause the green parts of Taiwan moss to stop growing. Maintain water temperatures between 75 and 82 degrees F. Taiwan moss will continue to grow in water temperatures of 82 degrees F. or slightly above but the leaves will be smaller and spaced farther apart on the stems. Add an aquarium heater to the tank if there is not one already present or adjust the temperature setting if there is a heater in the tank. Adjust the temperature very gradually to avoid shocking the plants and fish if they are present in the tank.

Lighting

• Insufficient lighting will cause the green parts of the Taiwan moss to stop growing or grow very slowly. The leaves that do grow will be unusually small and pale green. Make sure the light source is appropriate for plant growth. There are aquarium lights designed specifically to promote plant growth. Full spectrum fluorescent bulbs closely resemble natural sunlight. Make sure the light source gives off light in the red spectrum. If fluorescent bulbs are used, change them every six to twelve months to maintain consistent light output.