Help with Algae outbreak

[BigEarsNYC]

Hello forum,

For a few months I've been battle an algae outbreak in my DT. I attribute it to 2 things, first being taking and leave a few corals out the water for too long while repositioning and fragging (2-3 months ago) and second I added a Henioucus (long fin bannerfish) to the tank about 1.5 months ago. The fish would not eat the pellets that I typically fed to the tank, so I made frozen food and added it without washing the food.

The problem is that the algae has overgrown about 80% of a 6" birdsnest coral, is growing heavily on the rocks, and is growing on other coral frags.

I've added a lawnmower blenny who will not eat the algae. I've added a sea hare who will not eat the algae. I have a hefty CUC with emerald crabs, blue and red hermits, various snails (about 75 members in all), a big turbo snail who doesn't touch it either.

My phosphates and nitrates are zero. I've cut back on the frozen food to hand feeding the banner fish only every other day. The rest of the tank gets a small amount of Omega One fish pellets. I've kept the day lights off but the tank get bright indirect light from a southern facing window (I don't think lighting is the problem). I've had consistent water changes for the past month averaging 10-20g weekly.

I have a 2yo - 60g DT with about 20g sump
Protein skimmer, chaeto, fern macro algae
6" yellow tang, 2 clowns, blenny, Heniochus, long spinned urchin (also supposed to eat algae). I have many frags of soft and hard corals. My Duncans have not been happy for a while, my green monti has algae and green slime on it (cutting back the lights does not help this)
Purple Stylo, red mushrooms, leather toad stool, chalice are thriving.

My RODI filters are probably a year old but my TDS meter reads zero. I reordered new filters today.

Questions I have - will dead coral leak phosphates into the tank that will feed the algae in the DT?

Will the dead parts of the birdsnest coral grow back (as it appears to be doing from the base) or should I cut and remove 80% of the coral that covered in the algae?

Is this algae 'special' since no one seems to enjoy eating it?

Should I get phosphate reactor?

I realize the first step in troubleshooting is finding the source of the problem. I've ruled out lighting and over feeding. It appears my RODI is OK.

I can't keep weeding the algae out by hand each week. I need to try something new. Any help will be appreciated

Thanks

 

[BigEarsNYC]

One more note that I will make if it helps to diagnose the problem....

I don't suction my sandbed in my DT. A few weeks go I used a turkey baster and the power head to blast the rocks loose of dietrus. If anyone recommends tending to the sandbed I am open to suggestions.

 

[Loose tenticle]

Are you usinng R/O water,if you are might want to double check your membranes and filters. I had a horrific algae out break until i checked the membranes on the R\O it was sludge in there.

 

[BigEarsNYC]

Rodi

Yes - RODI. the filters are a at least a year old and I ordered replacements today. I haven't looked inside the membrane but here is a pic of the unit as of this afternoon. WHEN is the time to replace filters - when they change a dark color, when the TDS meter reads above zero, or after a period of X months? My TDS reading was zero as of last week - I'm still swapping out the filters tho.

 

[Loose tenticle]

I would say yours defenitely need to be replaced, and check the membranes. As soon as i changed mine it started to go away. Membranes i think depends on usage but i would say about once a year and the other filters every three months if you do weekly water changes.

 

[Loose tenticle]

Do you happen to have the tank near a window?

 

[Lenny718]

The reason you have zero nitrates and PO4 is because all of the algae is using it up. I would test the TDS of the water coming out of your RO and start running GFO or another type of phosphate media ASAP.

 

[BigEarsNYC]

I've kept the day lights off but the tank get bright indirect light from a southern facing window (I don't think lighting is the problem).

My RODI filters are probably a year old but my TDS meter reads zero. I reordered new filters today.

I just removed the large birdsnest with the most amount of algae, scrubbed it with a toothbrush and then sprayed with H2O2. I'll post back if I have any success.

 

[Clink51]

i would also run some phosban. wouldnt hurt. It helped me out with my algae issue a while ago

 

[androsreef]

pick alot of hermit crabs

 

[Aquadicted]

oh man it sounds like you're really doing everything possible... You def shouldn't blast ur sand in the fuge. If I had to guess I would say that's where the issue came from because everything else you did was right..

 

[BigEarsNYC]

Update on GHA

I thought I'd give an update to my GHA problem if anyone is following along and especially has any additional advice.

I still have large percentage of my rock with GHA covering it. It also is on much of my hard corals. I've installed a GFO reactor and am running 75g (60G tank) along with 50g of carbon. About 2 weeks ago, I stopped using the tank lights completely and for 3 days blocked all light (ambient form the window) to the tank. The results were positive with a weakening of the algae but negative since it also bleached some of my corals (frog spawn and hard corals)

I've started to monitor my Ma, Ca, and KH levels closer. My levels have been pretty consistent with the following:
Ma 1400 - 1500 (most of the time 1500)
Kh 7.6 - 9.1 (most of the time at about 8)
Ca 275 - 380 (mostly 370)
I'm testing with Red Sea test kit

My salinity is constant at 1.026. Phosphates, nitrates, nitrites, PH, ammonia are always zero or within an acceptable range.

I'm not exactly clear on the relationship between Ma, Kh, and CA even though I've read quite a bit on it. It seems my Ma is high and my Ca and Kh are low. I'm not sure how to get these in balance. Does it have anything to do with amount of hard corals that I have in the tank (soaking up the calcium)? Does the GHA effect these numbers? I experimented adding baking soda and epsom salts without a noticeable effect. I also was not consistent with this mostly due to my lack of understanding.

I added 20 hermit crabs 2 days ago.

I am thinking about another 3 day black out but am afraid that I'll lose some of the corals that are already.

I have a sock on the return which i swap out ever 3-5 days. I cleaned my skimmer wheel and it is pulling green tea consistency. I have chaeto and macro algae in the sump with a 24hr light. There is a black substance collecting that the bottom of my GFO media.

This problem started at least 4 months ago. The tank is over 2 years old.

Any insight will be appreciated.