Brown diatoms?

[Ashurbarnipal]

So I've been noticing brown growth on some of my rocks in my tank which cycled roughly a month ago. It mostly seems to affect one particular rock and some of the rocks around, but there's at least one rock that's been totally untouched by it, which was far away from it, but still under as much light.

Here are pics of some of the rocks affected:

The main rock:








It's also worth noting that neither my hermit nor emerald crab shows the slightest interest in the stuff, and it doesn't even want to come off like algae either.

My chemistry as of this morning is

0 ppm ammonia
0 ppm nitrate (though I've not yet got a salifert nitrate kit, so using the API here)
0 ppm phosphate

[Cliff]

Likely just diatoms.

The below links might be of some help to validate that

http://www.chucksaddiction.com/hitchhikers.html

http://www.reefkeeping.com/issues/20...ides/index.php

[Ashurbarnipal]

Well, if they are diatoms, the only thing I can think that'd make them grow in my take is silicas. The phosphate absorbing pouch I got did say it absorbed them as well, so perhaps it'll solve it

That or just that my tank is new and they'd go away with time

[Cliff]

They will go away with time

A bag of chemi-pure can also help

http://www.aquaticcommunity.com/revi...ct=465&cat=500

[Ashurbarnipal]

Aha, thanks. Well, as long as it's normal, I'm not too worried.

[Surfdog]

All my salt tanks started out with Brownish/redish Diatoms. I left em alone and they went away, now replaced with Coraline algae. It's just part of the process. Mine took about 2 weeks to disapear on thier own...But do look for a dark red coating, that would be red slime. It comes off by rubbing it. If you see that you will want to treat the tank. I used Ultralife Red slime remover, worked like a charm with 1 application. I installed a UV unit and have not had a re-occurance...

Good luck

[Jenni72]

I am having the diatoms too, today they were the worst I have seen them, but I have read they are a normal art of the process. I have also had them in freshwater tanks & they have went away on their own.

[Ashurbarnipal]

Well, I'm honestly not sure if the diatoms are receding or not, though coralline has definitely been increasing.

There are red spots appearing too, but they don't seem to be slimy. Took some pics of them and highlighted them with black:

[Cliff]

If they do not rub off, it's coraline

[Ashurbarnipal]

They don't. I just checked. Even tried working one with my fingernail a bit.

In that case, there's MUCH more coralline growth than I realized!