I was approached by a neighbor regarding his 60 gallon tank. I was aware about his large tank - and he told me that he keeps several others as well, although I have not seen them - but from our conversations, he does not seem to be a particularly knowledgeable fish keeper. I have noticed in the past when I visited him that the tank seems to be constantly dirty, and is frequently overpopulated. He has a very high turnover of fish - which is certainly a bad sign. I can't imagine that he is caring for them properly. I have discussed this with him in the past, but to no avail.
He approached me now because there is some sort of black growth that he keeps finding on the gravel, and can not get rid of. He removes as much as he can by hand every time he changes the water (weekly, though I don't know what percent of the tank), and it grows back to cover the entire tank bottom with in a few days.
I agreed to take a look. Currently, the tank does not seem overpopulated, but it is filthy. Everything is dirty. The growth he asked me about is something I have never seen before. It is black and fluffy, with occasional green bits mixed in, and covers almost the entire bottom, as he said. It sits on the topmost layer of gravel, and can be 'peeled' up in large, slightly sticky sheets, taking only a few pieces of gravel with it.
When I called me I was out, and I stopped off by him on my way home, so I was not able to bring a kit to measure any of the tank parameters.
Here are a few pictures (the gravel is also black, so it is a bit difficult to see):
He approached me now because there is some sort of black growth that he keeps finding on the gravel, and can not get rid of. He removes as much as he can by hand every time he changes the water (weekly, though I don't know what percent of the tank), and it grows back to cover the entire tank bottom with in a few days.
I agreed to take a look. Currently, the tank does not seem overpopulated, but it is filthy. Everything is dirty. The growth he asked me about is something I have never seen before. It is black and fluffy, with occasional green bits mixed in, and covers almost the entire bottom, as he said. It sits on the topmost layer of gravel, and can be 'peeled' up in large, slightly sticky sheets, taking only a few pieces of gravel with it.
When I called me I was out, and I stopped off by him on my way home, so I was not able to bring a kit to measure any of the tank parameters.
Here are a few pictures (the gravel is also black, so it is a bit difficult to see):