Whatever it was, it cleared up in any 2 day’s and tank has been great ever since. Damsel was evicted and I introduced a Royal Gramma & a Picasso Clown my neighbor gave me. I did order a UV sterilizer just in case for the future. Next up is to setup Eheim Autofeeder.Looks like dinos. You'd need a microscope to get a positive ID. Could be a mix of diatoms and dinos given tank age, but looks like the dinos are dominant. I'd run UV as a precaution if you have it and get a positive ID on it. For amphidinium dinos, UV is useless, but for ostreopsis and prorocentrum you should see noticeable results within days. #1 trick for dinos that I've experienced and see from others is introducing some sort of microbiome diversity to out-compete the dinos, whether that's reef mud, reef sand, ocean rocks, rocks/sand from an established system, etc. Dosing silicates to increase the diatom population is also popular. Once the diatoms clear the dinos and then the diatoms get cleared, there's still the "space left behind", which is real estate for the same dinos to come back or another species of dinos. Aquabiomics has some of their "cleaner" real reef products in stock again: https://aquabiomics.com/product-category/biological-supplements