Black Mold/fungus

[henpen9699]

I need your help. I recently purchased a used 125 gallon fish tank and set it up in my classroom. The sell also include his old driftwood, gravel, and rocks. About three weeks after I set up the tank, the tank became very cloudy and had a very high amount of ammonia. Even one day after a 1/3 water change, I measured 6 ppm. I also started noticing black or grey fungus growing on some of the rocks and floating on the top of the tank. Amazingly, the 12 small fish that I have to help me cycle the tank are all doing well.

After many water changes, I decided to replace all of the gravel, remove the driftwood, and clean of all of the rocks. When I refilled the tank and turned on the my two fluval filters, the tank was flooded with the black/grey fungus. What do I need to do to get rid of this stuff? A worker at the petsmart told me that I need to run bleach through the tank. I think that this is a very bad idea, but also want to get started so that my kids can enjoy a few fish before the summer.

Thanks.

 

[dkpate]

If it is algae, you can do a blackout. Hopefully someone knows something else too!

 

[Blueiz]

I need your help. I recently purchased a used 125 gallon fish tank and set it up in my classroom. The sell also include his old driftwood, gravel, and rocks. About three weeks after I set up the tank, the tank became very cloudy and had a very high amount of ammonia. Even one day after a 1/3 water change, I measured 6 ppm. I also started noticing black or grey fungus growing on some of the rocks and floating on the top of the tank. Amazingly, the 12 small fish that I have to help me cycle the tank are all doing well.

After many water changes, I decided to replace all of the gravel, remove the driftwood, and clean of all of the rocks. When I refilled the tank and turned on the my two fluval filters, the tank was flooded with the black/grey fungus. What do I need to do to get rid of this stuff? A worker at the petsmart told me that I need to run bleach through the tank. I think that this is a very bad idea, but also want to get started so that my kids can enjoy a few fish before the summer.

Thanks.

Did you clean your filter before you turned it back on? If not, this "stuff" could have been in it and when you turned the filter on it spewed it back into the tank. It almost sounds to me like uneaten food that is molding.

Do not run bleach through the tank. While I agree this will work, it is a bit overkill and I would use it as a last resort only. If you do this, you will have to start from scratch with the cycle.

It almost sounds to be like blue/gree algae, however a better description is needed. Does this stuff stick to anything? What kind of lights do you have on the tank? What are the 12 fish you have in it? What do you feed them?

Do you have a picture of the tank so we can see exactly what your talking about?

 

[joy13]

I hope I am wrong but it sounds like black brush algae.

 

[henpen9699]

Thanks for this advice. After another couple of hours searching, my guess is that it is blue-green algae (cyano). It looks like someone blew their nose with grey snot in the tank. I'm pretty certain its not brush algae because it easily brushes away. I'm headed to school now, I'll take a picture if I can.

 

[Blueiz]

Lots of water changes, removing what you can during each, and cleaning the filter often should help you to combat this and eventually be rid of it. Of course, this is tentative advise, depending on a correct ID of what you are dealing with ..