Is this detritus?

[Sushiboy225]

Hello, I’ve had a bad red cyanobacteria outbreak. I just blasted my live rock with a turkey baster and am about to vacuum the sand. I noticed this weird fuzzy, filamentous stuff that I guess was beneath the champ bacteria. Does anyone know what it is? I’m beginning to think it’s algae detritus from the Cyanobacteria covering it. Any idea would be great tho.

I recently got a ro/di unit recently and have done only 2 water changes of about 15% using the high quality water. Will this just be an over time of clean water changes it will clear up with actively cleaning the rock and sand bed?

Biocube 32 - 5 months old

Parameters
Ammonia: 0
Nitrites: 0
dKH: 8.1
Phosphates: 0.1 ppm
Nitrates: 5ppm
Salinity: 1.023
pH: 8.2

 

[footgal]

Detritus will be a small pile of almost powdery dusty stuff on the bottom of your tank, that looks like something else but I woul still try to brush and suck it out

 

[Sushiboy225]

Detritus will be a small pile of almost powdery dusty stuff on the bottom of your tank, that looks like something else but I woul still try to brush and suck it out

I’ve brushed most of it off but some is stuck really on there. Do you know what it looks like or what it could be?