Brown Discoloration of Top Sand...What is causing it?

[WhiteCloud]

My 40 gallon tank is 4 months old. I have noticed recently that the top part of the sand is turning quite brown in some places. You can really notice it when the Pistol Shrimp does some digging and the sand from deeper in the tank is so much whiter in comparison. It is not the red slime of cyanobacteria...been there...done that.

Any idea what may be causing this? I have about 15x water flow in the tank with the 2 powerheads and the skimmer. Could I need more water flow??

Any idea how I can clean it up some...it is looking a little "ghetto" in my otherwise immaculate tank. I was wondering if perhaps a cucumber or something could help clean things up a bit.

Thanks

WC

 

[SoylentGrundy]

I had it in my 30 and it came and went on its own...are you using RO/DI? I've heard water higher in phosphates/silicates prolongs the stuff. I may be incorrect but this is a diatom bloom?

 

[WhiteCloud]

I'm am using RO/DI water...and that is the only water I had used in the tank. Phosphates have always tested 0 ppm. I have never tested for Silicates as I had only used RO/DI water...and that tests out at 0 ppm with a TDS meter.

This is why I can understand why I am having this brown.

Thanks,

WC

 

[i have crabs]

its the diatoms
they feed on silicate in the water
silicate/phosphate sponge will clear it up

 

[JPloman]

I would increase my clean up crew.

A lot of times you will have your sand turn brown because of extra waste from the fish and other critters in the tank (not diatoms). It sounds like you have a full load in your tank, thus increaseing the clean up crew should help with this problem. I would say more hermits and maybe some brittle stars. You might also want to increase your amount of sand sifting snails.

 

[juskeepswiming]

or sand sifting stars

 

[demodiki]

I had this problem and after the addition of some astrea snails...4 of them!...it has cleared right up. My rocks were covered with diatoms but now...just rock