What is this black stuff in my aquarium?

Answer by  BrentByers (39)

It's probably the poop from your fish that you just bough at Petsmart last week. Unfornutaley, you forgot that fish poop and that they can be very difficult to clean

Answer by  Don73 (90)

If it is within the rocks or floor of the tank it is most likely fish excrement. Check to make sure that you are not over crowding your tank. An over crowded tank can create stress on the fish. Also, if you are over feeding your fish, this will cause the fish to increase waste production.

Answer by  Amy78 (30)

I've frequently had a problem with black "slime" in my aquariums over the years. It's a form of algae, and it seems to spread quickly once it appears. If you are looking to get rid of it, you will need to clean your tank and balance the PH.

Answer by  Nemo (29)

The black stuff is algae, it can also be red, brown, or green. You can buy an algae brush to scrub the interior of the aquarium.

Answer by  writersblock (11)

What you have sounds like an algae problem. You can control the growth of algae by limiting the lighting your tank gets, as well as doing partial water changes.

Answer by  aratliff (111)

The black stuff is Beard Algae and is very hard to get rid of. You need to clean your take completely and soak all plants and any gravel in a beach solution then scrape the algae off of them. For the next month you need to do at least a 25% water change, and limit light.