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Brown algae and dying corals

20K views 8 replies 6 participants last post by  kaya 
#1 ·
Over the last while, we've had a continuous problem with some strange brown algae, the best way I can describe it would be to say it looks like dying hair algae except it's not dying, it grows and it grows fairly fast, in the sand it just seems like a light brown film over the top and it doesn't seem to grow on the corals much but we're having a hard time getting rid of it.

A few pictures:




Like I said, it doesn't seem to grow on the corals too much but I'm sure it can't be too good for them. Two of the corals (a staghorn and a brain coral) seem to be dying, the brain coral for sure. The staghorn no longer has polyps coming out of it and seems to have a brown film growing on it


The brain coral, from what I can tell, started off fine for a long time and eventually a small piece of it was under some sort of algae and eventually died, the fairly small dead piece enventually spread through the coral and now most of it is dead.

What would be the thing to do with this coral? is it pretty much gone or do we cut the dead part off or what? The other part seems quite healthy actually.

Some specs:
we have 2 400w metal halides and 410w fluorescent lights
Skimmer and a denitrator running
We add Purp Up and Coral Accel most days, kalkwasser is added mixed in with fresh water.
Water tested about every 3 days and the levels seem to be fine, nitrates are 0 or close to 0, PH is fine, nitrites fine, everything seems to be fine.

We clean the tank regularly and try to get as much of that algae off the rocks as we can in 1 go but it always seems to come back. I'm not sure what the problem could be, any advice would be appreciated. If you need more pictures or certain test results, just say. Thanks.
 
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#2 ·
You say you're adding purple up and coral accel, but do you test for what these products add? If not, I'd recommend immediately stopping their use. What are your calcium, alkalinity, magnesium, salinity, temperature levels, and how big is the tank?

The algae looks a bit like bryopsis, and it's taken over. It can be quite hard to kill, though I've heard elevated alkalinity levels can aid in it's demise. It also appears that you have some cyanobacteria.

Also, you don't describe flow in the tank. What's that like? Do you have a skimmer?

With the limited data I have now, it appears that you have a lot of excess nutrients in the tank that are fueling algae and killing the few corals you have remaining (likely in the form of phosphates, though nitrates are very likely too). I'd recommend getting antoher nitrate test and posting the results. I don't want to give you zero hope, you can overcome the problems you're facing, but it will take a long time and a lot of effort. There is no overnight solution. I imagine the quickest fix for getting rid of the algaes and creating an atmosphere for coral to thrive would be to start over with new live rock and live sand, but that may not be an option. The other choice is to start with water changes, a couple 10% changes a week, beef up your filtration, cut back on your feeding (what are you doing now), and keep at it.

Sorry, probably more rambling than you prefer!
 
#3 ·
The brain looks like it may be exposed to flow that is to strong. Did you test Nitrite or just assume it was negative because of the amount of time the tank has been running? Denitrifying filters can produce nitrite that can cause algae blooms and kill coral. I thought these filters were gone, but this is the third thread involving these filters in the past week. Where do you get your fresh water? Do you have herbivores like tangs?
 
#4 ·
i agree with crvz, although when testing the test kits may be inaccurate because the algae is probably consuming almost all of the nutrients that are in the tank. i would test with a tds meter, are you using RO/DI water ??

another question would be, how long are the lights on for during the photo period ??
 
#6 ·
Thanks for the replies so far, I should have added a little more info..

The tank is a 55g. Temperatures are usually around 78, sometimes a TINY bit lower or higher (76-80 maybe?) I'm not 100% sure how to describe the flow in the tank but we have.. maybe 5 different pumps in the tank, a few of them rotate and the others are basically a "wide jet?"
Last time I checked the nitrates (2 or so days ago) they were at about 0.5(ppm?) The calcium and alkalinity levels are where they're supposed to be, I'm not 100% sure of the magnesium or salinity levels, I'll have to check them. We have a skimmer running and we get our fresh water from an RO.

Hopefully this will help, time to sleep.
 
#7 ·
Hmm, can you post specific values for calc and alk when you check the mag and salinity?

The existance of nitrates and phosphates can be masked due to the large amount of algae in the tank. Even though you're getting a low value, it could easily be that the source of nitrates is still there, it's just being used up very quickly. I'd still start an aggressive water change regimen and cut way back on whatever you're adding to the tank (food wise especially).
 
#9 ·
I had the exact same problem, I even tried to scrape the surface of the live rock with a dremel, it still came back, and killed most of my corals,

you need to reduce light, and the time your lights are on, do water changes as often as possible, pull it off as much as you can as often as you can and need to buy something that eats it, sea slugs, couple of BIG turbo snails, if it is on a rock piece you can spare put the rock in your refigium (if you have one) or a separate tank with no light,
I bought two giant Turbo snails, and removed the sand I have a 12 g, so that was enough,
they keep it under control and now I have no problem.
good luck
Kaya
 
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