brown stuff on sand

[acasden]

Help- I have had my tank for 5 years without problems and recently have a brown color to sand in spots. Nothing has changed that I know of, temp, ph all parameter are unchanged over the years.

If i mix the sand it comes back in the same spots- starting to grow on rocks also, it is a brown discoloration to the sand,

Anyone see this before?

 

[Ben1]

Cyno or diatoms or dinos, hard to tell with out pics or a beter discription. Whats the water test out at?

 

[acasden]

At the risk of sounding simplistic i know all the parameters are fine, pH about 8.0, phosphates 0, all fine. I have a guy who helps take care of the tank and all numbers are right on target- i have a phospate reactor, protein skimmer, refugium, ca reactor. It is gross, please help.

 

[Anonymous]

Did the water flow in the tank change in any way?

Cyano tends to prefer areas of lower flow.

 

[Ben1]

Still with out a better discription we cant help. Go through the search or google diatoms, dinoflagellates, and cyanobacteria. Once you know what it is there are different solutions.

If it is cyano I would not recommend using antibiotics, like chemiclean. Instead find the source of the pollution and eliminate it. How often do you do water changes and what type of water is used for this and top off?

If the problem is always on the sand it might be that the tanks flow need adjustment and the sand bed could be caked with detritus leeching out nutrients as it breaks down in the sand.

Do the search on google image or here on RDO and let us know what matchs your issue or post pictures.

 

[Anonymous]

Also aging lights can make that problem worse.

 

[acasden]

Thanks, I will do this,
Actinics are about 2 years old, metal halides rather new.

No new change in water flow,

It is so suprising after 2 years without a problem.

 

[Anonymous]

Just remember to cut down on the time the lights are on once you change the bulbs and gradually bring it back up again so the corals get acclimated to the more intense light.

 

[snapper1]

Diatoms