Corals Dying

[Moogled]

My tank's been running for about a year now, and lately some of the corals are dying.

My Merulina plate coral started turning white on the edges and it has been slowly creeping across the coral; now it's almost half dead. I tried scrubbing the algae growth on the skeleton but it doesn't seem to be coming off. I dose Calcium regularly but I think there may be another problem. Corals don't seem to thrive in my tank with the exception of a Donut coral and a Scolymia

I'll post my water parameters tonight.

Any wide guesses as to what's happening or does the "whatareyourwaterparameters?" always apply?

Thanks in advance,

Marco

[michika]

What kind of lights are you running?

[Moogled]

I'm using a 36" 4 bulb Tek Light.

It doesn't seem to be an improvement from my crappy Coralife T5s.

However, the spectrum is very blue from the 2 actinic bulbs and I'm wondering if I should have three 10ks/ one actinic rather than two bulbs for each.

[untamed]

I would propose the "What have you recently changed?" question?

[michika]

Originally Posted by Moogled

I'll post my water parameters tonight.

What did your parameters turn out to be?

[Moogled]

Sorry, I went out to buy new test kits just in case these older ones wouldn't work.

I did a 30% water change two weeks ago with another 10% the day after. My nitrites were coming up as 0.25.

My current parameters are:

Ammonia: 0.25
Nitrate: 0
Nitrite: Undetectable

I do regular water changes and feed moderately and try to keep Ammonia as low as possible. I've had this tank for almost a year now, shouldn't ammonia be undetectable unless it was a spike? All my fish are fine and swim around happily. There's no odd behaviour (e.g gills showing) of any sort.

[fkshiu]

0.25 ppm ammonia is a potentially deadly spike if accurate. Re-test immediately.

Have you lost any fish lately? There may be something rotting away in an unseen corner.

Ca and Alk levels would also be helpful.

[Moogled]

I haven't lost any fish lately; they're all very healthy.

My Ca levels are around 450 and I don't have any Alk measuring kits.

However, there is some detritus accumulation in one corner of the tank - I didn't think much of it because I usually siphon my tank very clean every time I do a WC.

[Der_Iron_Chef]

Have you implemented a phosphate reactor or anything lately? Anything that could potentially initiate an algae die-off?

I could test your Alk for you if you lived nearby....or someone else could if they live nearby.

[andsoitgoes]

You just changed your lights about a month ago, you posted about that, didn't you?

Why not try changing back? Obviously that change is the only major thing youv'e done on your system.