Acan and favio help

[romperstomper]

Hi
sorry first post is for help from over the water ,been running marine for around 4 years using ATI essentails tank has newish sand ( 4 months) live rock moved over from old tank along with corals and fish, lighting is kessils .All stats are within NSW levels ,except NO3 at 25 (a little high)corals are zoas and LPS all corals doing well except for the two top pictures ,acan and a favio which are clearly dying ,other acan in last picture is doing very well in the same tank ,have been reading this forum with interest for some time and would like some of your knowledge on where I'm going wrong ,any help gratefully received .

 

[ngoodermuth]

That bottom colony looks to be doing ok I know you mentioned in your intro thread you aren't skimming or doing water-changes... are you using ICP tests to check your trace elements? I'm following along, I don't know enough about this type of system to offer any good advice but I'm interested in learning more.

 

[romperstomper]

Thats a good point and have to admit that I don't do icp tests ,ATI essentails does replenish trace elements along with the basics though , all other corals seem to be thriving ,I have tried moving these corals too but that does not seem to help .

 

[Reef Bazaar]

How stable is your alk and mg ? Acans in general are very delicate when it comes to alk swings -- i.e. measure alk before light turn on, and measure alk right when lights turn off -- what's the difference?

The favia seems like it was stung by something -- either in your tank or before it got to you. In either case, I'd advise monitor the tank params -- keep everything as stable as possible -- and move them both to lower light -- away from each other. The favia can easily kill the acan with its tentacles.

 

[romperstomper]

I dose daily by hand into the sump as I don't trust dosers but my tanks usage is low , alk is normally around 8.5 ,mag was low on last test at 1200 which I increased to 1350 a bit faster than I should have (24 hours )but the two corals have been struggling for a long time now .
The favia was doing well until I had to move him as he was stinging my duncans along with everthing else near him and has gone down hill since ,the acan has struggled ever since I bought him around a year ago but my other acan puffs up and does well (last picture).
Will try lower light ,thanks .

 

[romperstomper]

Think I may well have found the problem after reading a thread on here , tested my PO4 which is Zero not really surprising considering I have cheato ,fluval clearmax,polyfilter and rowa running and NO3 at 25 ,have to admit I did not know that some LPS corals need PO4 (I say some as my duncans are happy as larry,but then I guess they are good food grabbers) .Anyway I have taken the rowa offline and increased feedings .

 

[mike_zackary]

I find they like very low light and slow flow. They seem to thrive and do better for me