SPS dying and looking for advice pls

[Ivar67]

Hi Everyone

I have a 1000L tank thats been running for a year. About 6 months ago I started adding SPS and all was going well. The montis and acros you see in the pictures I have had since they were frags. The last month things have started to go rapidly downhill and I don't know why. I have had a guy here from the local LFS, and he is as puzzled as I am. I have had nothing major happening to the tank but everything has been stable. I have changed the lighting somewhat in intensity and color.
As you can se on the pictures the montis look terrible, except the growth areas.
I have similar browning on one of my acros, they'll one in the picture, which polyps are receeding rapidly.
The other problem, if there is two, look very much like an alk spike to me. Refer to the picture with the Green acro with white tips, this is how all my acros look today.
I test my water every week and I can say with confidence that I have had no alk spikes.
Today my LPS are doing well. Two months ago I had two hammers receding, my LFS took them on and they died, interestingly they had other hammers dying in that tank afterwards, did my hammers bring something with them ?

I would very much appreciate your feedback, not funny watching a tank slowly go down.
Thx

magnus

here is my setup

1000L tank
250L sump
Pac sun hyperion lamp, using Bali program at 55% intensity
3 jebao RW 25´s
Kore 5th doser dosing Randys cal and alk.
Waterchange 300L/month

Water parameters

salt 1.025
Alk 8.5 stable in the 8`s
cal 450
mag 1260
nitrate around 20
phos .05

 

[xdestry]

Can you think of anything you changed in the tank right before it started to go downhill?

Mag seems a bit low and nitrate a bit high but I don't know whether those would cause the sps to die off. Maybe raise mag to around 1400?

 

[rt67ghy]

Did you run GAC after you noticed problems with your LPS's? It could be an issue of allelopathy from chemicals released by dying LPS's.

 

[Ivar67]

I forgot to say I use rowa and GAC but only in the two little fishes small reactors so I don't think the GAC amount i use would have helped much in cleaning the water after the hammers died. rt67ghy, do you know more about this?
Would a massive GAC reactor clean the water from whatever it is? What does GAC actually extract from the water?

thx for your help

 

[toothman]

Your tank will just do better if you reduce your nitrate down to 2ppm, by what ever method water change, carbon dosing, gravel vac or all three. May be a rough ride with nitrates that high.

Also bump mg dosing to 1400

Would not hurt to check. K also.

GAC is good in small doses, if too much is added it will stn acros.

 

[rt67ghy]

I forgot to say I use rowa and GAC but only in the two little fishes small reactors so I don't think the GAC amount i use would have helped much in cleaning the water after the hammers died. rt67ghy, do you know more about this?
Would a massive GAC reactor clean the water from whatever it is? What does GAC actually extract from the water?

thx for your help

The dying corals would release organics which would affect sps corals. But running a large amount of GAC for 3 days would probably bind it all and prevent problems. After 3 days I would dump the GAC and return to your regular quantity. GAC binds all types of organics and many types of chemicals/toxins released into the water.

 

[rt67ghy]

Although not exactly the problem you faced, I read a thread where someone upgraded to a bigger tank. He used the same sand which he washed in aq water and rocks, 50% of old tank water. After putting all the corals (including some massive acros) into new tank he ran GAC quantity 3X (in grams) to volume of water in new system (in litres). e.g 1800 grams of GAC for 600 litres for 3 days to absorb all the organics that he anticipated would be released by his corals. This project he documented well and the final display was amazing with no signs of stress in any corals. I tried finding the thread but wasn't successful but will try again.