Hello Serial. I didn't see anything other than new plants developing. Some algae is beneficial. You won't find a better water filter. Just remove a little at a time, so it doesn't get out of control. If it looks like it is, just add some Anacharis to the tank. It's a floating plant that will use the excess nitrogen in the water and will slow the growth of algae. Java fern is an excellent choice for your tank. So easy to grow and interesting to see the plant develop from the leaves of the mother plant. I have a land plant that grows very much like this aquatic fern. It's called "Queen of the Evening". The new leaves grow from the older ones. I've included a picture.
