no green algae growing?

[Kit with Cat]

Hi everyone, I have a super newbie question here:
In the previous months, despite having a HOB refugium full of chaeto, there would always be green algae growing on the HOB aquaclear filters and the HOB skimmer that I have. The algae would actually grow on the slope of the return of these units. When the algae does grow, I would scrape it off and put it into the tank and my hippo tang would snatch it up really quickly.
Now, I noticed that there's no green algae growing at all. I thought, great! Now I can totally expect to see my rocks turn purple from coralline algae! But that totally didn't happen. In fact, I think my live rocks look the same color as the day I got them.

Question is...why has green algae (my hippo tang's veggies) stopped growing all of a sudden and why does coralline algae not grow ON the live rocks? Coralline algae has no problems growing all over the glass and equipment but just won't grow on the live rocks.

Only thing that's ever died in my tank is a cowrie (it died in 2 days), and two barnacle blennies (I think my dottyback ate them).

Thanks in advance!!!


My params:
90G tank, setup for 6 months.
T5's 3 white 3 blue, 8 hours of light
Nitrates - 0
Nitrites - 0
NH4 - 0

Livestock:
2 x false perculas
1 x hippo tang
1 x bicolor dottyback
1 x diamond goby
1 x pom pom crab
1 x emerald crab
1 x yellow cucumber
1 x tuxedo urchin
CUC - 10 snails, 10 red legged hermits, 3 neiseria snails, 2 cleaner shrimp, 1 peppermint shrimp
Corals - Pulsing Xenia, Blasto, Ricordea, Green Pallies, Assorted Buttons, Mushrooms, Kenyan Tree Coral, Leather, Green star polyps, frogspawn, hammer, torch coral, montipora, maxima clam

[spit.fire]

whats your salinity?
phosphate levels?

[Kit with Cat]

Thanks for the response!
Salinity = 1.025
Phosphate = 0

[reefwars]

you should get a look at your other parameters like cal,mg, and alk.having no green algae........ some would consider great.if your coraline isnt turning white and its on the glass then it will spread but depending on what your other testings are could be the reason you dont see any on the rocks grow.do you have any urchins?? some can chew up coraline pretty good

[Kit with Cat]

Come to think of it, a lot of the coralline on my back glass is turning white. Will test all those params tomorrow. Thanks so much!

[Kit with Cat]

Alk - 110mg/L
Calcium - 420-440mg/L

I've actually never tested these before....is that good?

[Bloodasp]

Alk is slightly low I think. Ca is just ok. Have they been exposed to air?

[Kit with Cat]

Sorry has what been exposed to air?

[doch]

Coraline that gets exposed to air will die and turn white. What kind of rocks... live or dry? I find that the dry rocks seem to take a while to get purple growth... not sure why. The green stuff probably stopped growing due to lack of nutrients... that's a good thing!

[jostafew]

Hey everyone, thought I would follow along, I have a similar problem (very little green algae growth but a fair bit of brown, poor coraline growth)