Algae, Bacteria or Diatom Bloom?

[AquaRaider44]

Looking for some help on this one.

My tank is pretty cloudy and has some sort of red-brown slime covering the rocks.

What is this and what causes it?

I am running an AquaUV at the recommended flow rate for total sterilization.

All corals seem to be super happy even the acros have polyps fully extended. No recent changes, other than removing algae scrubber because my nutrients were already low and it didn't grow much algae.

Stopped dosing aminos and trace since this started two days ago.

Phos - 0.03 ppm
nitrate - 1-5 ppm
calcium - 410 ppm
alk - 11 dkh
mag - 1450 ppm

 

[j.falk]

Holy smokes...that is a TON of coral in that tank.

 

[j.falk]

@ReefSquad

 

[AquaRaider44]

Holy smokes...that is a TON of coral in that tank.

Yes I know. #reefsquad I am still in need of help.

 

[j.falk]

Yes I know. #reefsquad I am still in need of help.

Sorry. I forgot this place uses hashtags....Nano-reef uses the @. My bad.

 

[Bulletsponge]

I would think its just the algae using up the nutrients that were used by the scrubber. Even if the algae in the scrubber didn't seem to grow, it was using nutrients in some amount. This algae is just filling the void and using the extra nutrients available

 

[AquaRaider44]

This is so weird. In an hour while I left my house to get lunch I come back and the tank is 90% clear just like that with no explanation. Thank you guys

 

[brandon429]

its time for a giant water change on this great reef tank. refresh it out, change about 90% of it. there are brs threads and hobbyist threads on big tank water changes, they help here and it wont harm anything *if you pour back carefully such that sandbed waste isnt strewn about*

the params for the tank need to be matched to what it takes to grow coral, solely. not what it takes to possibly starve the invader needing hand guiding/that can stress corals.

regarding the light invasion, its time for hand-detailing/peroxide scraping where possible on hard surfaces outside the tank like surgery over the sink, not via the water. this tank has ran hands off as long as you can stand it/go opposite hands on. big work, but thats the price of an awesome large reef if cuc animals arent working/matched to the task