I have a 50 litre aquarium that currently houses a couple of sparkling gouramis, 6 ember tetras and 3 otocinclus. I recently brought a new light for the tank and now there is algae on the glass and a very thick fluffy coating on a couple of rocks. I think it looks cool on the back of the tank and the rocks and it is easy enough to scrape it off the front glass. I was just wondering if there is any harm in leaving it or do I need to scrape it off.
Thanks