Dino outbreak - Cant raise phosphates

[NicholasP]

Hello everyone, I had po4 issues (po4>3ppm), that I managed to overcome with skimming and a refugium, but the problem is for the past two weeks I have lots of brown hairy algae with some bubbles I suspect are dinos. My no3 fluctuates around 10ppm, but my phosphates are less than 0,03, probably zero on my tests.
I am trying to raise phosphates but to no avail.
I run the skimmer 24/7 and my refugium for 10 hours with an inverse light cycle.
Should I turn off the skimmer for a few days and dose some coral food? I've been feeding heavily and have a pretty stocked tank (2 clowns, 2 lysismata shrimps, 1 sunburst Butterflyfish, 2 azure damsels, 1 hermit, 1 derasa clam and one astrea), but my phosphates won't budge. Even checked with a Hanna checker.
I will try to remove as much w vacuuming and dosing some diy coral snow

 

[NicholasP]

Also tank params:
Salinity 35ppt
Ph 8.4
Alkalinity 7.5dkh
Calcium 450ppm
Magnesium 1500ppm
Nh4 0ppm
No2 0.5ppm
No3 10ppm
Po4 <0.03ppm
Volume 300L, around 280-270 with substrate, rock and skimmer displacement

 

[Reef.]

3ppm to 0.03 po4 with a skimmer and refug seems a little too good to be true, might not be dinos and whatever it is its using the po4 to breed so your po4 may not be as low as you think.

My advice is to confirm as best you can what you have and if dinos, either go for uv if they disappear at night or the scrub and remove method if they dont, scrub rocks and vacuum sand at least once a day into a 1 micron filter sock, the idea is to physically remove as many as you can, if feeding a lot etc I would not worry about upping numbers until you see they are stopping reproducing then see where your nutrients are at…you really need a hanna checker yourself as the other tests are not great.

 

[NicholasP]

3ppm to 0.03 po4 with a skimmer and refug seems a little too good to be true, might not be dinos and whatever it is its using the po4 to breed so your po4 may not be as low as you think.

My advice is to confirm as best you can what you have and if dinos, either go for uv if they disappear at night or the scrub and remove method if they dont, scrub rocks and vacuum sand at least once a day into a 1 micron filter sock, the idea is to physically remove as many as you can, if feeding a lot etc I would not worry about upping numbers until you see they are stopping reproducing then see where your nutrients are at…you really need a hanna checker yourself as the other tests are not great

Thank you for your advice. I have not noticed their behavior at night to be honest. I have a phosphate Hanna checker that the previous owner of the aquarium gave to me, and I use it.
The only diff w the drop test kit that I use is that the drop test is pretty aquarate but below 0.05ppm I can't make out the color differences.
I will try to manually remove as much of it as I can and see

 

[NicholasP]

I will post photos of the infestation as soon as I get home