Dying Lps


So I didn’t think anything of this until now... but first I had a Duncan die on me, then another Duncan, started to die, now my blastomussa which has grown like 3 new polyps in a couple months is starting to die. Everything else in my tank is fine. Idk what is wrong. I just thought maybe I couldn’t keep Duncan’s alive but now that one of the corals that was growing is starting to die I’m thinking it’s something else.

Again, I find it odd that it’s only one coral that’s dying at a time, so it’s not my tank parameters.... I have a maxI minI anemone that’s fine. A hammer that’s fine. Some ricordea that are fine, and some zoas and GSP that are doing fine. My clown fish and clown goby are also good.

Last night I kept looking in my tank to see if it was a hermit crab or something eating them, and, I didn’t see anything on or eating the coral, so I don’t think it’s that.

Anyone have ideas or suggestions at what’s causing this and if I can possibly save the coral, and prevent others from dying??


Well, I just got home and my lights are on in my tank, and the blasto seems to be doing better, it’s not fully opened but it’s not completely closed up either


Well... you can't really say it's not your parameters based on the happiness or madness of other corals, and certainly not based on fish behavior. This is because corals, above all, like stability. Stability in lighting, salinity, and the levels of The Big Three, which are calcium, magnesium, and alkalinity. Here's my story and what I can base this advice on...

About a year and a half into our reef tank and finally, some basics were automated. We had the ATO running to manage salinity, finally had the right light set at the right level, and an automatic doser to keep up with maintaining levels of alkalinity and calcium... because we finally had enough coral and they were growing enough for considerable uptake of these minerals. So, to prevent alk and calc from dropping too much between water changes (and making our corals angry due to the change), the automatic doser was installed and carefully set to dose the precise amount of alk and calc that our tank was using in a day.

Now, I'm not saying that you need to dose. Shoot, it took us a year and a bunch of small coral frags growing into small colonies before the weekly water changes couldn't keep up, and thus, we had to dose at this point. Okay, so... on to the issue.

Several months later, all of a sudden, a few of my corals were quite mad. It started with maybe 4 out of, idk, but more than 20. The majority of the corals appeared fine but I was looking for an explanation for the 4 angry ones... a test revealed that my alkalinity level was at 7.5. It should have been at 9. We discovered that my preteen, by mistake, had unplugged the doser three days prior. 7.5 isn't horrible and our tank's alkalinity had hovered there for quite a while before installing the doser. Corals weren't mad then... but we had carefully raised and maintained alkalinity at 9 for several months, and the sudden drop back to 7.5 was bad news. Carefully, slowly, we brought it back up to 9... but it was a little late. A few more corals got angry, until there were 8 or 10 I was concerned for, and this occurred after the fix! The thing is, corals are sometimes slow to react... some corals are fast to react, but all of them took a loooong time to get over this error on our part.

Just to show you how variable corals can be, get this... I had a purple tip hammer with 5 heads and right next to it, a green tip with 2 heads. The purple got mad as heck during all this and in the end, lost 2 of its heads. Meanwhile, the green was happy all along and not too long after the dosing debacle, it started to split into 3 heads. Another example... I have 5 acan corals, all very near to each other and receiving similar light intensity. During and for weeks after the dosing debacle, a single acan colony was closed and angry, while the rest were happy as clams. I even have an SPS example! My birdsnest and montiporas seemed fine during it all, but the acros and porites took it the hardest. Some changed color and looked as if they were browning. 3 of my favorites, all SPS, did not have ANY polyp extension for about 2 months. I was sure I'd lose them but did all I could do... kept a stable tank. Eventually, they all came back, with zero loss of the colonies. Funny thing is, I would swear that one slow growing acro has grown faster since the mistake. Could it be kinda like plants in that, a stressful period may bring on extra growth afterward? Idk, but it seems so.

Anyhow, this is just to show you how different corals will react differently. Also, variations in your tank may have occurred without you knowing, and even if things are fine now, the corals could be reacting to instability.

On another note, I'm sorry, this isn't to pick on you... but Duncans are hardy corals. Generally, and in my own experience, more so than zoanthids and other softies. Plus, they are quick growers once established and fun to feed. For these reasons, a Duncan is often what I recommend for a first coral. Now, you should definitely look at your source when losing corals. Maybe they were never very healthy to begin with. However, only a careful eye, plenty of observation, and lots of testing will tell you how things are going with your water and your tank's stability.

Hope this helps. Good luck!!


Yes, thankyou! It’s incredible how different corals are! I figured out after a couple nights of surveillance it was my strawberry crab! It ate it’s way through two Duncan’s and started on my blasto. Fished him out of the tank and the blasto is happy again. I’m just glad I figured it out before it died. (Crab was returned to LFS) Anyways your response will probably help me in the future, knowing that just because most corals look good, doesn’t mean everything is going good in my tank.

(I had tested my Params and everything was the same as always which is why I was sure that wasn’t the problem this time.)


Yay! I'm so glad that you found the culprit! Hmmm, I don't trust crabs... at all. People might call me crazy but I went the first year and half swearing that I would always remain crabless. I only had snails for CUC. Hmmm, it took me a long time to fully stock the tank and as time went by corals were added and grew. Certainly, by this time, I was feeding the tank more than I had previously. Except, I never worried much about feeding, since 4 or so months into the tank, we retrofitted an Aquaclear 70 HOB so it could work as a filter and a refugium. Ever since beginning to grow chaeto there nitrates and phosphates remained almost immeasurably low (this doesn't mean that I am a fan of or promote running an ultra-low nutrient tank.) Well, eventually there must have come a point where nutrient uptake by the chaeto wasn't enough for the now fully stocked tank. I STILL couldn't ever find nitrates over 5ppm or phosphates over .05ppm. However... for the first time, after all that time, green hair algae (gha) began to rear its ugly head. It didn't start out bad but, of course, it spread over time. Still, test readings weren't alarming, NO3 almost always being zero, PO4 never reaching one, so the simple answer is that (gha) was taking up excess nutrients (also, that PO4 was higher than NO3, bringing my tank out of the Redfield Ratio... google if you're interested).

I eventually got a pretty good handle on the gha. It's not gone, but there's much less and it isn't much of a nuisance anymore. What changed was... I finally added crabs, plus a PO4 reducer (ChemiPure Blue), and went back to a method I used in the first months of my tank which I highly suspect was a huge help in keeping my tank algae free for so long. It's called floss and toss and I'll be happy to explain if you want... just feel I'm getting off topic here. The point is, I was very nervous about adding crabs to my tank. So... I did lots of research and bugged lots of reefer buddies before settling on a female emerald crab and some tiny blue-legged, reef safe (hrmm), hermit crabs. So far, they have been nothing but a blessing and I see them eating from places where I can't even see algae anymore, (wish I could get them to go after the longer stuff that's in places which are impossible to scrub without hurting corals.) It took a while but I've even come to love them... even the emerald. Yet, I still don't trust them and the minute I see a crab attacking corals, they are banished from the tank.

So, imo, you've done well in identifying the problem and taking care of it. Too bad it lost you a couple Duncans, but that's over now and you've saved the Blasto, hurray! I'd highly suggest you try with the Duncan again. A Duncan was one of my first, a single polyp added, ohhh, probably 18 months ago I guess. He's a big guy now with more polyps than I can count though the last time I did he was at 24. Also, I just think they're gorgeous corals which can mimic the look of a large anemone without the danger of a nem moving around stinging things in the tank. Plus, they are fun to feed and very hardy in my experience. When my guy was little, I think at about 5 polyps, with 4 of them still small/growing, he had a nasty run-in with a torch coral. Sadly, that torch was my first big loss and as he was dying, tentacles came off, floated around, and at least one got snatched up by the big daddy polyp on my Duncan. Oh boy, but he looked bad for quite a long time... but the polyp survived and the colony thrived. Duncans are simply awesome!!


I actually have some GHA I’m trying to get rid of now, I’m also running an hob refugium and have chemI pure blue going as well.... sadly my blue legged hermits don’t really seem interested in it at all... (I’m glad my hermits haven’t decided to eat corals!!) maybe I will try another Duncan in the future but right now I’m focusing on getting my 90 gallon ready to just plug in and go once I move, so funds are kinda limited for my nano as of right now. I might look into getting a emerald though, I really love crabs and think they are interesting but after this, the trust level is low.


Forget the various things that may or may not work. Go with Fluconazole. As long as you let it sit for a month and follow the recommended dosage it will definitely wipe out the hair algae for you. You just need to make sure once it has done it's thing that you do a sizeable water change after the treatment to get rid of all the nitrates that the GHA released when they died. Fluconazole breaks down Bryopsis (Hair Algae Family) down on the cellular level.

Here is my tank before treatment (notice all the hairy gunk in the rockwork):

Here is the tank after the month long treatment and then doing a big water change and waiting for another week:

You need to make sure you remove your filter media during the dosage (although Chaeto will be perfectly fine during the treatment).



Hmm maybe I’ll give it a try.

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