Just diatoms... There feeding off silicates in the sand and water... Just let them burn out.. You can leave the lights off a couple days also since it's only a fowlr....
Thanks for the feedback. The only reason I post this is because I've been having issues with my fish. I added a LemonPeel angelfish 3 weeks ago. 3 days after I added it, my cleaner shrimp dissappeared. Then a week after that, my Pearly Jawfish dissappeared and stopped eating, only to be found later, still alive, but pale and laboring underneath is rock (since has dissappeared again). Then 2 days ago my LemonPeel died, which was excepted because the thing wouldn't eat anything I put in the tank.
How did you cycle the tank??? Diatoms are honestly the last part of the cycle... Your tank just might be ready for fish now... One or 2 a week at max...
I cycled it in 4 weeks. Just dosed the tank with some ammonia and let the cycle do its thing, I also bought Dr Tims Nitrifying Bacteria, just do add it in but not actually to rely on it.