acro STN

[chris&barb]

im starting to get some STN on some of my acros. the only changes I've made was a new skimmer about 3-4 weeks ago. i had NO3 levels of 2 to 5ppm before the skimmer change and over the 3-4 weeks this skimmer has been running it has dropped my NO3 to .2ppm. PO4 has been 0 (no color change, Salifert) for months. Alk is 9.6dkh(dosing pump, no swings),Ca 400ppm(dosing pump also)Ph 8.15(pinpoint)

whats going on?

what should i do?

 

[Ohgee]

Kind of curious what kind of acro's your talking about. From my experience, both good and bad, STN can be caused by several things and some of them have little or nothing to do with tank parameters you listed off.

I am curently having some problems but that is due to a major swap in tanks and a serious flow change. I've also assisted a friend who had no changes going on in his tank and things simply started to RTN.

Hopefully someone with a little more knowledge will jump in here to assist, as I would like some different ideas as well.

Has your lighting changed at all in the last 3-4 weeks, new bulbs or such?

One thing you can do is frag the ones that are STN'ing sometimes that will help from loosing the entire colony. I know from my experience I've at least been able to save peices.

Hope someone else jumps in soon for you

Duane

 

[chris&barb]

humalis(sp)

i know i can frag it but the whole colony would be destroyed. the main part is deep in the center at the base, and then i would have an acro crab with out a home.

 

[NaH2O]

Where is the STN taking place? From the base, on the branches, at the tips? It might be as simple as the dropped nutrients. How long have the corals been STNing?

I'm taking over some corals that were STNing and not looking very good. When I brought them home, I noticed acro eating flatworms on them. Just something to keep in the back of your mind. I'm not sure if you've looked for parasites yet. Were these acro colonies or frags? How long have you had them, and when was the last acro addition to the tank?

 

[bradreef]

pests can be one of the big stn things lately. I would look very carfully at that. also nutrients, but it sounds like you are going in the right direction. if your water cleared up to fast you would probably bleach and not stn. Run carbon. also it could be chemical. check you mag, cal, alk, ph, then do a big water change. 25% I have taken out all my coral and done a super strong iodine soak before. I cant recomend the strenght I used.

 

[chris&barb]

Where is the STN taking place? From the base, on the branches, at the tips? It might be as simple as the dropped nutrients. How long have the corals been STNing?

I'm taking over some corals that were STNing and not looking very good. When I brought them home, I noticed acro eating flatworms on them. Just something to keep in the back of your mind. I'm not sure if you've looked for parasites yet. Were these acro colonies or frags? How long have you had them, and when was the last acro addition to the tank?

its deep down at the base and on a few tips, i noticed this 2 days ago

this one is a wild colony i got 1 1/2 years ago, when i got it it RTNed and i had to frag it in half but its been fine since.

i havent added any new corals in over 6 months.

i dont think i have any kind of bugs but i will look more closely

 

[chris&barb]

pests can be one of the big stn things lately. I would look very carfully at that. also nutrients, but it sounds like you are going in the right direction. if your water cleared up to fast you would probably bleach and not stn. Run carbon. also it could be chemical. check you mag, cal, alk, ph, then do a big water change. 25% I have taken out all my coral and done a super strong iodine soak before. I cant recomend the strenght I used.

mg,ca,alk and ph all good

i will add some fresh carbon

largest water change i can do is 10%(500gal system)

i was reading through Eric B. book and there was a mention of Lugo's(sp) and it also said that i could put a few drops on the effected parts(while still in the tank) what do you'all think about that?

 

[reedman]

I've had either a nasty parasite or some sort of pest killing corals throughout my tank. I have treated for red bugs, done water changes, etc and I'm still struggling.

Not sure what is going on lately, but it isn't fun. I wish you good luck with your tank.

 

[bradreef]

that is too bad too hear. I am sure we are going to run into the new trend of acro pests.

 

[NaH2O]

Chris&Barb - You say this has just been happening in the last 2 days? Did you notice a bleaching before the loss of tissue? Hopefully, Kevin will have some ideas for you.

Also, I don't know about using Lugol's while the coral is in the tank. It would be a concern to me, however, doing a dip outside the tank may be beneficial if the problem persists. You may need to remove the acro crab into a separate container until the coral goes back in the tank.

If the coral isn't encrusted, then you may want to take it out and give it a good look over. The colony I had with Acro Eating Flatworms had an egg mass in the center of the colony. I had to break off a bunch of branches to get at the egg mass. The eggs alone are quite small (I'd say about the size of the polyp), but I've only found them laid in a mass. You can check out the pictures in the thread: QT for Acro Eating Flatworms. It was suggested in the AEF thread, however, that corals with acro crabs don't usually have AEFs.

I'm not at all saying this is your problem, I'm just giving you a heads up. The AEFs I could not see when the corals were in the tank I took them from. It wasn't until inspecting them outside the tank that I found them.

 

[chris&barb]

no bleaching, in fact the color has never been better. about a week or 2 before i did notice less polyp extension. but on other unaffected corals i have the best extension ive had in a long time.

let me tell you a little more about whats been going on.

about 5 months ago my fuge went sexual(racemosa)60g fuge full of it.corals browned and stopped growing but otherwise looked fine. i did lots of water changes, phoslock. things were starting to get better then one pump on my skimmer went out(skimmer was a little under sized to begin with)so instead of getting a new pump i got a whole new skimmer but it took 3 weeks to get. ive been running this skimmer for 4 weeks or so and things were really looking better untill this.

 

[kevinpo]

Hello,
Sorry to hear about your coral troubles. IMO your alkalinity is running a little high. I like to see numbers around 8.3 dKh (2.97 meq/L). I'm not saying that is the cause though. I have seen A. humilis be sensitive to changes in lighting intensity caused by bulb replacement or changes in water clarity. Usually it lightens and then turns brown then light again before coloring up. Sometimes you can apply superglue over the area in contact with the good tissue creating a barrier from the receding part.
To be safe I would frag one branch and place it in a lower light area just in case the colony goes south.
I would also try dosing kalk for few days and see if the coral improves.

HTH,
Kevin

 

[chris&barb]

thanks for the reply Kevin

i do have some frags of this in my frag tank.

im just curious, why dose Kalk?

 

[kevinpo]

I have heard quite a few times from other hobbyists of stony corals showing a marked improvement (more healthy appearance) very soon after dosing kalk. The only scientific thing I know of is an increase of PH when dosing kalk. It will usually run about 8.3 - 8.4. I don't know if this is the reason for the improvement or not but because your parameters look within the range for keeping stony corals but I would give it a try. My chemistry is not too good so I can't give a perspective on the complete interaction of kalk that would cause improvements. Boomer would be the person for that.

Regards,
Kevin

 

[chris&barb]

Ok thanks again,

i have slacked off from dosing Kalk some since i got my dosing pumps on line. ive just been trying to automate things some so we can get out of the house for a few days. i guess ill have to set up a pump for kalk also

 

[kevinpo]

I wouldn't get too exotic. I would just try it manually for 4-5 days and see if there is a noticeable difference before setting up an automated system. I run kalk reactors on most my tanks but have had great success dosing just calcium chloride, magnesium, and buffer also.

You don't mention your magnesium ppm. It should be about 1200ppm for 400ppm calcium.

Regards,
Kevin

 

[chris&barb]

i keep Mg around 1250 to 1300ppm