Sand is turning brown in spots ???

[josey]

I have a 55 gallon reef that's been established for around six years. My pH is around 8.1 to 8.3 my calcium is 480 nitrate, nitrite .0, ammonia .0, phosphate .0 to .2 I do 10% water change every week and everything has been great but for the past week I've had brown spots coming up in my sand. I've had and kept the same regimen for 6 years expect this past week I used reef chili 3 times to feed my corals. Do you think this could be the problem? My sand has always been bright white now it looks burnt. I light with a fluvle 2.0 pro for 8 hours of light 4 hours of moon light and 12 hours dark. Any ideas of what could be wrong would be greatly appreciated.

 

[Becky]

Sounds like it could be diatoms - check out this topic here: Brown algae

Welcome to the forum, great to have you here! :)

 

[josey]

Thanks for the info Becky. I would think the same thing but it's not a new tank. Everything I've read has always refered back to the problem being with new tank set ups. My tank has been established for a little over 6 years now. Here's a pic of it.

 

[monique]

i think she may be right. my tank is 6 yrs old too. when i moved it i had to replace my sand. i could not get a hold on the cyno until i did that. i had absolutly no problem with algae before that. now i stir up the sand when i do a water change. sounds like maybe that food has given your diatom population the edge it needs. i drag the handle of a wooden spoon through the sand trying to lift it and and remove the sediment when i do my water changes. after the water clears i clean my filter and skimmer. this helped me a lot with my water quality. and i feed heavy. brine,mysis, new spectrum pellets, new ara algae pucks, and algae sheets.