Stubborn Algae? Diatom? Not sure....

[Bigbeezy]

I have a 55g Cichlid aquarium that is over a year old. I have always had issues with some discoloration on my rocks. This reddish-brown stuff has always been present to some extent. It is present on the rocks and on plastic items like my filter intake and outlet, but it doesn't grow on the glass. It takes a toothbrush scrubbing to remove it. I clean/PWC my aquarium on Saturdays, and it usually returns by the next weekend. I have black color quartz in my aquarium. I take very good care of my aquarium, keep the nitrates below 10, and have twice the necessary filtering. I have LED hood and usually run the lights about 10-12 hours per day. I've tried leaving the lights off for most of the day and it didn't make a difference.

What do you all think this stuff is? I've done a lot of research but I still haven't convinced myself that it's algae. Maybe Diatoms? I don't know... Here's 2 picture of it on my white rocks after cleaning. Comment please! Thanks!

 

[phoenixkiller]

Looks like diatoms. Stubborn stuff. Truthfully, my tank is more than 6 months old, and still has a diatoms problem.

Some say it will go away with time, I don't know if it will though.

I unfortunately don't have any advice on getting rid of it, except scrubbing, and perhaps some Nerite snails (They love algae of most types).

Hope I helped a bit!

 

[callisto9]

I have it too, though most reading I've done says it's (more) common in new tanks. I had it in my smaller 6.6 gallon and it went away. I now have it in my 20G tank and it's hideous. I'm going to cut down on the amount of light, as right now I run the light 16 hours a day. Cutting down to 10.

 

[phoenixkiller]

Best guess is that having lights on a timer or having nitrate sponge like plants in the tank should help with it, it's just a guess though.

 

[Cichlid Kid]

Diatoms feed on silicates in the new substrates, decor etc... Usually they'll go away within a year, sometimes sooner