I have a new 40 Gallon tank that I added 4 Serpia Tetra to on the 15th of January. I am using real plants and currently have the light (120 Watt 50 volt) on for 12 hours. Last week I started seeing a thick web like algea on the glass of the tank and a rust like algea on the leaves of my plants. I slowed down the amount of food over the last four days to nearly zero and have reduced the light to 10 hours per day. Any ideas????