So I've had this white/brown slime stuff for over a year now.
It started as a thin layer of almost slightly fuzzy white slime on the highest rock surface in my tank. Didn't seem much to worry about at the time.
It got worse over time, and for the year this stuff has been covering every single upwards facing rock surface in the tank.
Due to the fact that it only seems to be growing on upwards facing surfaces, I assume this stuff is highly photosynthetic.
Its very slimy and rather like snot. If not removed manually every 3 days or so it gets very out of control and becomes very thick with strings waving around off of it in places.
This tank sits at undetectable levels of nitrate if left without manual dosing. I believed this to be the cause of poor coral colour, poor polyp extension and STN/RTN of some SPS coral in this tank, therefore I began dosing sodium nitrate to maintain a nitrate level between 1ppm - 5ppm. This only increases the growth of this slime stuff, and seemed to have no impact on my corals, and in some cases could have caused further coral death / growth stagnation. Therefore I believe this slime stuff consumes vast amounts of nitrate and could be the reason for the tank wanting to sit at 0ppm without dosing.
There is also red cyanobacteria on the sand bed, this started 6 months ago and the white/brown slime took over before the cyano took hold on the sandbed.
I perform 10% water changes weekly with tropic marin pro reef salt and 0 TDS water from my RODI machine.
My LFS recommended trying their natural sea water to see if it could improve the biodiversity in the tank to outcompete this stuff whatever it is. So in the last two weeks i performed two seperate 10% water changes with this natural sea water and have seen absolutely zero visual change in the tank.
I tried dosing microbacter 7 weekly for around 2 months. Saw no change in anything.
Under the microscope this slime stuff is just mush. I can't make out anything identifyable between 100x-1000x magnification.
Current tank parameters:
tank volume - 100 litres (Red Sea Max Nano Penninsula)
nitrate - 1ppm
phosphate - 0.1ppm
calcium - 380ppm
magnesium - 1200ppm
alkalinity - 7dKH
temperature - 25.5c
salinty - 1.025sg
Lighting:
AI prime 16HD set to the AB+ spectrum at around 75% 10 inches from water surface.
Rocks are roughly a further 10 inches from the water surface.
The lighting was higher at 110% earlier on in this tank's life, as this was going to be an SPS tank originally before... this. But I have since turned the lighting down slowly over the course of over a month (around 3 months ago) and saw no change.
The tank was started with mainly dry rock and bio media blocks in the rear sump, plus one rock from a long time estabolished system at my LFS.
I have attached pictures of this stuff under white light.
What is this stuff man... I cannot find any pictures of this stuff anywhere, but hopefully SOMEONE will have seen it before.

It started as a thin layer of almost slightly fuzzy white slime on the highest rock surface in my tank. Didn't seem much to worry about at the time.
It got worse over time, and for the year this stuff has been covering every single upwards facing rock surface in the tank.
Due to the fact that it only seems to be growing on upwards facing surfaces, I assume this stuff is highly photosynthetic.
Its very slimy and rather like snot. If not removed manually every 3 days or so it gets very out of control and becomes very thick with strings waving around off of it in places.
This tank sits at undetectable levels of nitrate if left without manual dosing. I believed this to be the cause of poor coral colour, poor polyp extension and STN/RTN of some SPS coral in this tank, therefore I began dosing sodium nitrate to maintain a nitrate level between 1ppm - 5ppm. This only increases the growth of this slime stuff, and seemed to have no impact on my corals, and in some cases could have caused further coral death / growth stagnation. Therefore I believe this slime stuff consumes vast amounts of nitrate and could be the reason for the tank wanting to sit at 0ppm without dosing.
There is also red cyanobacteria on the sand bed, this started 6 months ago and the white/brown slime took over before the cyano took hold on the sandbed.
I perform 10% water changes weekly with tropic marin pro reef salt and 0 TDS water from my RODI machine.
My LFS recommended trying their natural sea water to see if it could improve the biodiversity in the tank to outcompete this stuff whatever it is. So in the last two weeks i performed two seperate 10% water changes with this natural sea water and have seen absolutely zero visual change in the tank.
I tried dosing microbacter 7 weekly for around 2 months. Saw no change in anything.
Under the microscope this slime stuff is just mush. I can't make out anything identifyable between 100x-1000x magnification.
Current tank parameters:
tank volume - 100 litres (Red Sea Max Nano Penninsula)
nitrate - 1ppm
phosphate - 0.1ppm
calcium - 380ppm
magnesium - 1200ppm
alkalinity - 7dKH
temperature - 25.5c
salinty - 1.025sg
Lighting:
AI prime 16HD set to the AB+ spectrum at around 75% 10 inches from water surface.
Rocks are roughly a further 10 inches from the water surface.
The lighting was higher at 110% earlier on in this tank's life, as this was going to be an SPS tank originally before... this. But I have since turned the lighting down slowly over the course of over a month (around 3 months ago) and saw no change.
The tank was started with mainly dry rock and bio media blocks in the rear sump, plus one rock from a long time estabolished system at my LFS.
I have attached pictures of this stuff under white light.
What is this stuff man... I cannot find any pictures of this stuff anywhere, but hopefully SOMEONE will have seen it before.

