not new to reefing but new to setting upa tank with a sump

[LUCKYLATO]

so the day came that I was able to set up a 90 gallon upstairs and put the sump in the basment all went well the new stand the tank the plumbing. I put my old live rock in the tank along with 60 other lbs on live rock I filled the tank with salt water I got from my LFS and put medium grade sand in.
it has been running for 7 days. I noticed yesterday that the older live rock in the tank turning brown green and today very heavy coat.
Should I do a 10% water change or let it run I have no cheato and neather does my LFS. Help please.

[ReeferChris]

I think your tank is just cycling. If you are running your lights I would turn them off. I would check to see if your tank has had an ammonia spike and just go through the steps of cycling a tank

[ajcanale]

Diatoms, completely normal.

[sponger0]

No reason to turn your lights off cause once you turn them back on, the problem will return.

[EllieSuz]

Diatoms come and go in new tank set-ups. Now is the time to practice your patience.

[Albert184445]

Ya that's what happened when I set up my new tank. The diatoms will go away