Brown muddy stuff on rocks

roc1hmr · Apr 12, 2020

What is this stuff? Tank is little over a year old and all of a sudden got this stuff on the rocks. Coraline gets covered in it then bleaches out and dies. Noticed phosphates 0 ,nitrates 4-5, alk 9, Ca 445, mg 1450. It’s a 40 gallon with 15 gallon sump. Lighting is 16 hours on lit by single Kessill 360. In sump I run Filter sock, skimmer, chateo. Weekly 5 gallon water changes. I’ve scrubbed this stuff off and it comes back.

ndrwater · Apr 12, 2020

It's algae. Pretty typical. If you want to try and keep it at Bay, shorten your lighting cycle. You definitely don't need 16 hours. 12 is more than enough. You could even go less if need be

Shawn_epicurious · Apr 12, 2020

I only have high intensity lights going for 8 hours a day right now. Tank full of fish and softies right now.... have your lights cycle the way you like them during your prime viewing hours. Unless you have SPS, you don’t need that much light : ) Some more snails would help...?

i say this everytime... I am not one of the experts here.....

roc1hmr · Apr 14, 2020

Could this be a cause of low phosphates? And how do I get rid of it I clean the glass and by next couple day’s I got a whole bunch of it on the glass.

roc1hmr · Apr 23, 2020

With my phosphates still at 0 should I consider dosing PO4? I feed heavily but my PO4 never rises. I have been testing weekly since February and cannot get PO4 to move up at all. Corals losing color and lost a frogspawn. would 0 phosphates be the cause of this dark brown stuff on rocks and poor coral health?

vetteguy53081 · Apr 23, 2020

Looks like the start of dinoflagellates. I would reduce white lighting, increase water flow a little aimed at tank bottom, add a little Bacteria supplement daily and 1ml of peroxide per 10 gallons at night. You will slowly see this go away in about a week. Loosen up with a turkey baster daily and net up the loose particles and rinse the net out thoroughly

roc1hmr · Apr 23, 2020

vetteguy53081 said:
Looks like the start of dinoflagellates. I would reduce white lighting, increase water flow a little aimed at tank bottom, add a little Bacteria supplement daily and 1ml of peroxide per 10 gallons at night. You will slowly see this go away in about a week. Loosen up with a turkey baster daily and net up the loose particles and rinse the net out thoroughly

Thank you for the advice. What about my PO4 you think I should dose?