Sounds like diatoms. Comes with new tank pretty much and lack of flow. Make sure you keep up with good tank husbandry, rinse you frozen food, use ro or rodi water, have plenty of flow and it will go away in time. My tanks seemed to get better after about the 6 month time frame, but I have had one that took longer.
Funs not over yet though.LOL Once thats gone you might hit other algae stage, but might not. If you do just be patient and keep taking care of the tank and before you know it you will have a mature pretty tank without all the nasty stuff.