Rocks turning rusty/black

[bubbs]

All of a sudden, the rocks in my tank have got a coating of what looks like rust , or heavy dust on them.

From having a lovely clear clean tank I have been infested with this horrible rusty coloured 'something'. Its even on the plants. The leaves are turning black / dark brown on their edges.

Please can anyone advise on how to clean up my tank again, and What is it?

I do regualar water changes each week approx 15% and the light is on 8 hrs a day. All this has not changed , so what has?


Thanks in advance

 

[Tempestuousfury]

Probably diatoms.

Caused by too much nitrates and minerals and not enough light.

Solutions:
Newer lights (and change to fluorescent if you're using incandescent).
Less food.
Less fish.
More frequent or greater % of water changes.

 

[Moe]

Could be green slime algae. It is often brownish in color. If you tank out one of the rocks and it feels slimy and rubs off easily I'd say it's algae. You can get a few otto, they will eat it and are small and don't add much to your bio load. If the plants are fake you could also try an apple snail they'll also do the job.

 

[bubbs]

thanks for replying.

tempestuousfury mentioned minerals, does the carbon filter sift minerals out? Only temp'fury's response reminded me that I had to remove the carbon filter for 4 days due to medication, and this is when the problem started.

(both fish sadly died) and the carbon filter has gone back now.

Do diatoms go by themselves? or should I scrub the rocks or simply replace them? Tank looks awful at the moment.