Very slow, over six months

[Sparkpaul]

I have a colony that is thriving. It is getting good growth but it is dying from the bottom up very slowly.

I have 200g sps dominant.
Parameters 8.5 alk, phosphate 0.04 nitrate 5ppm, calc 470, mag 1380

Lights 2x250 radium 200k

What's the cause?

 

[shih87]

What about your light and currents?

Anyway, it doesn't seem too bad to me, have you check if flat warm bother its root?

 

[sahin]

How is the water flow? It is a large colony...sometimes a lack of water flow can be a cause.

Have you also checked out the Potassium level? I was having a similar issue for many months...after having checked the usual parameters, I found out my Potassium was like 290ppm.

I bought some Potassium Chloride salt and brought up the Potassium level over the course of a week. The few corals that had slow recession around the base reversed and started to grow back.

Also make sure you've checked for pests etc by basting a few corals and also dipping any if possible.

 

[trueblackpercula]

From my experience when acros STN at base is caused by not feeding and high alk.

 

[trueblackpercula]

Also by the look of how's it's growing it appears it is growing away from the light lol

 

[Sparkpaul]

Potassium is at 420 and alk is around 8.4. I don't feed very much but it is growing toward the light.

Flow, i have two eheim 1260 return and two 6105.

I will try feeding and basting. I'm afraid to dip, will it exacerbate the stn?

 

[sahin]

Dont dip the affected coral, ie the one in the photos...that would be quite stressful on a coral which is already not doing so well. I mean another smaller colony, just to rule out pests.

 

[Sparkpaul]

What about your light and currents?

Anyway, it doesn't seem too bad to me, have you check if flat warm bother its root?

2x250w radium and 4x kz purple

 

[mayjong]

hard to tell from the pic, but are you sure it's stn and not just shaded/white?
like on the bottom side of a efflo or other tabling sps?
those are white, too

 

[UTCReefer]

Lack flow can cause the base to slowly die back. I see it happen from time to time in my tank too. Other times with lack of light the coral base is just very light in color and almost bleached looking but its not dead because i can still see PE everywhere

 

[Trevor40]

Is there a coral right below it almost touching it? I'm thinking its getting stung.

 

[Sparkpaul]

Is there a coral right below it almost touching it? I'm thinking its getting stung.

There is a red tabling acro on the bottom of it but they haven't touched yet. I thought it will turn white be it turns black.

The base is black and dead with some crud on it. Maybe there is no flow there, dead spot. I'll add a powerhead.

 

[sahin]

The base is black and dead with some crud on it. Maybe there is no flow there, dead spot. I'll add a powerhead.

If you can remove the coral out of the tank, I would quickly scrap the crud off. I got a large SPS frag last week. On the base a small section had a bit of crud and that part was dead/decaying. Before I put the frag into my tank, I scraped off the crud making sure I scraped a little into the SPS tissue.

A week later and last night I checked, the coral is growing this part back nicely.

 

[mayjong]

oh, didn't realize that black used to be coral!