I am noticing an Algae growth in my 30 gal freshwater tank. I have a variety of fish Australian Rainbows, Neon Tetras, Blue/Red Tetras and Zebra Danio's there are about 15 fish in the tank. This Algae is very dark sorta a deep red purple. It is growing on the rocks, the wood and some on the tank. I have cleaned the tank several times in the past 30 days and continued to check the water. The water composition is all within the safe areas. I am wondering if maybe I have a culture in the filtration system which spreads to the tank. Any comments or ideas are welcome.
Don
Don