Brown Algae on glass (mature tank)

[Lil Puff]

Hi, I have a 450 litre (120 gallon) mature (1 year and 10 months old) predator reef tank that is having trouble with algae.

Parameters:
Phosphate - 0.10ppm (Hanna checker)
Nitrate - 100ppm (Salifert test kit)
Ph - 8.3

I am having problems with brown algae (diatoms?) that completely covers the glass overnight after being completely cleaned. If not cleaned for a long time it can get stringy but it doesn't have air bubbles although, in one area of the tank on the glass that doesn't often get cleaned there is a brown stringy algae that does have bubbles (Dinos?) - I'm not sure if they are the same algae. The problem could be my nitrates and phosphates which I am trying to battle with chaeto which isn't growing at all as I think I am low on iron and other minerals (going to get some chaeto grow) and it also gets covered in brown algae. I am also running a 57 watt uv sterilizer which is way oversized for my tank and it didn't make a difference in how fast the algae grows at all compared to when I didn't have it. I have also been running gfo in a reactor on and off to keep phosphates down as they were around .30ppm before. Any help on how to get rid of this algae would be appreciated!

Photos below *white light was only on for photos*:
Photo of algae on the front panel through the side panel

Photo of what I think is dinos on the overflow

Photo of algae on return

Full tank shot

 

[ReeferTang44]

How long are your lights on and at what intensity?

 

[Doctorgori]

you got a refugium?
Edit add: I don’t trip on nitrate that much or measure, but 100 ppm might be a lil excessive. Also that tank doesn’t look very mature. Recommend large water changes and maybe cut back on the food.

 

[Lil Puff]

How long are your lights on and at what intensity?

My lights are PopBloom RS90 which slowly dim and rise between times.

Channel 1 (8000k white):
12am - 9:30am = 0%
9:30am - 2:30pm =35%
2:30pm - 4:30pm = 20%
4:30pm - 12am = 0%
Channel 2 (Moonlight)
12am - 6:30am = 0%
6:30am - 9am = 5%
9am - 4pm = 100%
4pm - 8pm = 5%
8pm - 12am = 0%
Channel 3 (REEF GROW Blue)
12am - 5:20am = 0%
5:20am - 9:20am = 5%
9:20am - 2:40pm = 100%
2:4pm - 6pm = 30%
6pm - 8pm = 5%
8pm - 12am = 0%
Channel 4 (Cyan Blue)
12am - 7am = 0%
7am - 10am = 70%
10am- 6pm = 100%
6pm - 8pm = 50%
8pm - 12am = 0%

 

[Lil Puff]

you got a refugium?
Edit add: I don’t trip on nitrate that much or measure, but 100 ppm might be a lil excessive. Also that tank doesn’t look very mature. Recommend large water changes and maybe cut back on the food.

I have an algae reactor. I thought a tank that has been running and had fish in it for nearly 2 years would have matured by now. At what point is a tank considered mature??

 

[Doctorgori]

I have an algae reactor. I thought a tank that has been running and had fish in it for nearly 2 years would have matured by now. At what point is a tank considered mature??

I was strictly looking at the coraline growth, which at 2yrs should be covering everything (or at least all the black plastic)….could be a function of those diatoms dominating, but something is definitely off.
BTW, just my opinion, but your growth doesn’t look like its enough to justify a reactor…nothing wrong with using one per se, but you might have better luck dosing Kalkwasser for a lil while anyway

 

[Bitcoin Reefer]

For the GHA and in general, tang gang.