Brown Algae Will Not Go Away!


New member
I have what looks like diatoms, which will not go away. I have been running Phosban in a reactor now for about the past two weeks plus carbon. I am diligent with RO water changes at 10% every week.

Salinity 1.026
PH 8.3
Nitrates 0 (Could this be a false reading?)

At this point in time I am running my lights on a 12 hour sunrise/sunset cycle at about 45% at its highest point in the day. I tried to cut the lights back to about 7 hours with really no difference.

Any help would be appreciated!


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New member
The sandbed looks almost reddish from my point of view. Can't really tell from those two shots. Try looking at it under pure white light if you can. If it's really reddish and not brown it might be cyano.


New member
I tried taking pictures under brighter light, but my camera sucks! In either case, help would be appreciated.


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New member
How old is your tank? Diatoms are a usually in new tanks or if you changed something big sand bed. They tend to go away on their own over time.


New member
I got two small conch shells from the fist store.

They got this "elephant trunk" they use to suck up the brown stuff on the bottom.

They cleaned 75% of my tank floor overnight.

Highly recommended.


New member
Not 100% sure but it looks somewhat like the algae I have in my tank and my emerald crab eats the stuff non-stop. It never fully goes away but he certainly keeps it at an acceptable level.

Tom G


New member
I am considering increasing my flow with 2 Koralia 425gph pumps and using my smartwave controller. Do you think this is overkill considering what I have already?