brown substrate

[Zack]

Hello
My reef tank has been up and going for about 2 years now. However on the sand i am starting to see some brown dust like algae. Been going on for a couple weeks. Any idea what it is.
I have a 50 gallon
400 watt MH and 2 28 watt PC's
15 gallon fuge 60lbs of rock.

any thoughts??

[Zack]

PIC:

[microreefguy]

it might be cyanobacteria. maybe the same family. a type of slime algea perhaps. too much nitrates, phosphate, or nutrients. then again, i don't know all that much. :|

[MikeS]

Hey Zack

I'm thinking that looks a lot like a diatom bloom. have you done anything to the tank recently? I know diatoms are a new tank prob usually, but I still will get them from time to time, esp if I move the tank, add rock, ect.....
MikeJS

[Zack]

Hey
Can't thinkl of much, i did add some new lighting, i use to have 400 watt MG now i have a 400 watt MH with actinics...

[Rock Anemone]

Most likely the lighting upgrade caused it. This is perfectly normal. The best you can do is to keep doing regular waterchanges and using good quality carbon.

Rock Anemone :D

[Charles Poole]

Diatoms usually spike due to increased silicate levels. After the initial breakin of course. When my RO membrane started to go bad, this happened to me. After replacing it, the problem went away in a week or so.

*** Note *** Most basic RO units do a poor job at silicate removal. The use of a High Silicate removing membrane and DI cartridge are needed to appreciably lower the levels of this chemical. This is onw of the reasons that RO/DI units came into play in our hobby. ***

Check you water source for silicates... :)