Cycle question- brown spots

[ThisisJCarts]

Hi all, long time lurker, first time poster!

I have recently upgraded by tank from a roughly 35 gallon to a Red Sea Peninsula 350 G2. I have used the rock from the previous tank but all other equipment and sand etc is new. It has been running for about 9 days now and all seems well. However I noticed this morning before work that the tank was starting to develop brown spots on the glass and in the sand (pics added) it feels really early to start noticing anything like this, could it just be because this is the furthest point from my powerheads / return pumps? Thank you very much for any help in advance!

(I know my peninsula is up against the wall but it was the only place I could put jt after many discussions with the better half!) Can take better pictures if needed! Was in a rush this morning.

 

[ThisisJCarts]

Also, forgot to add I haven't been running my skimmer and lights, should I turn the skimmer on? Thank you!!

 

[brandon429]

the transfer of systems inevitably involves castings of waste/detritus attachments on rocks and other items moved over

under bright new lighting these substrates may begin to sustain algae and cyano mixed in, primary producers on any new reef, just treat it like waste and siphon it out during usual maintenance.

 

[ThisisJCarts]

Thank you very much!

 

[MnFish1]

The answer IMHO - is you should start your skimmer. There would be no reason not to. Best wishes with your new tank