Diatoms Or Brown Algae?

Just in the last few days I've noticed a rapid increase of brown diatoms/algae.
If I use my mag-float, and get it all off the glass, it comes back in 2 days or so to the same amount.

There's also some red/green spots in the sand bed.

The brown stuff on the sand seems concentrated in a few areas, and then dusted in others.

Is it just plain brown algae or diatoms?
My tank is about 6 weeks old now, and has 4 fish and a few corals.

My Phosphates were high, but I'm running GFO and a protein skimmer. Also an Emperor 400, and doing weekly water changes of like 5% or so.

Nitrate was at about a 10PPM last night, Ammonia 0/Nitrite 0, KH 9, Calcium was higher around 520

Thoughts?

Tank from front and side



Back glass


Front


Big Spot Of It


Pinkish Green Stuff In Sand

 

Looks like diatoms..for a 6 week old tank, thats pretty normal IMO.

Should take its course and be okay in short time. just keep taking the magfloat to it on the glass

 

When I do magfloat the glass, I just let whatever happens happen. Should I be trying to suck out the brown stuff?
I can't see an easy way of doing that.

So I guess it comes off the glass and just goes someplace else.

Will lowering phosphates help?
I was real high like a month ago, .82.
Now with the skimmer, gfo, and WCs I've got it down to .10 last week.
But I can't seem to drop it further.

 

Yea looks like diatoms too me as well, and as zoanthid21 posted your tank is pretty new, just give it some time. BTW you are probably going to see the development of green hair algae next, something to look forward to.:

 

I mean, with my tank..I always have natural algae in my tank that is brown that grows on the glass..But i just scrape it off once or twice a week..

But since your tank has been up for 6 weeks, im guessing the cycle just got done, so your just going through the steps. It will run its course in a few days and be gone.

Just when you do a water change you can use a siphon with a gravel vac attached and just suck it up. But phosphates and nitrates are the cause of the diatom bloom, thats why everyone gets it because they spike in the cycle.

Increase your water changes to about 25% a week.

 

The only thing with the siphon is, it really doesn't pick up tue brown stuff since it has to weight you know.
So I just have to suck up the whole sand, and then I lose it

 

Wier Head

it does look a lot like diatoms
and the time line indicates diatoms are the most likely at this stage

I would leave it, it will burn itself out once all the silicates are used up
no action required at all, if it is diatoms

it should be all over and gone in 4 - 6 weeks
it may last longer if your using tap water, as that can provide additional silicates
and thus prolong their life span

Steve