diatoms or cyano?

[Lynn52]

I upgraded to a 125 about a month ago. Everything from my 55 (rock, sand, water, sump and livestock) was moved to the new tank. I had a mini cycle that lasted a few days. The last week to 10 days I have had a brownish something (I figure either diatoms or cyano) growing on my sand. Every morning it is completely gone then when the lights come on it comes back. I have a good sized CUC including a sea hare that keep things in pretty good shape most of the time. I am leaning toward diatoms because it isn't on the rocks and not particularly slimy looking.

What do you think?

 

[zesty]

yeah, I'd say diatoms as well.

 

[puffer420]

Hey I just went through the same process of upgrading my 55 to a 125 with 30 gallon sump setup the only thing I did different is and 100 lbs of new sand and used the old sand in my sump. It's about 3inchs deep to try and reduce some nitrates naturally but I still have the same brown diatoms in my sand still after a month but they are lighter in color so thing things are starting to balance out. I'd add your cuc.