I hope to stave off bashing from a misdiagnosis. After examining the thread carefully, you are dealing with Marine Velvet not Brooklynella. Don't know what I was thinking. I guess I was going by the first picture alone.
Velvet (Amyloodinium):Symptoms - Because velvet can be such a fast killer, key behavioral symptoms will often prelude visible ones. A fish with velvet may breathe heavy, seek relief by swimming into the flow of a powerhead and act reclusive (velvet makes them sensitive to light).
If visible symptoms do manifest; velvet appears the same as ich, except the fish will usually be covered in “dust.” This dust may look gold colored if viewed at the right angle and under the right spectrum of light. Velvet is often misdiagnosed as ich and is the main “tank killer” in our hobby. It can wipe out all your fish in less than 72 hours and cannot usually be “managed” as ich sometimes is.
Treatment options - Chloroquine phosphate is the treatment of choice for velvet, but copper also works if symptoms are caught early on. Tank transfer and hypo does not work with velvet. A freshwater dip or formalin bath is recommended before treatment begins, due to the severity of this disease; however these would only provide temporary relief and will not eradicate velvet.