Green Staghorn Acro and Red Montipora dieing....

[camaroguy]

Hi SPS experts. I have a green Staghorn Acro and a Red Monti that seem to be dieing off. Both of these showed really good growth around summer/fall of last year.

Earlier this year I noticed my Green Hydnophora was dieing off, and realized that my nitrates had gotten really high around 80ppm. I have been using NOPOX and regular water changes since to bring the nitrates down. I am now down to ~8ppm and holding around that number.

Other stats are as follows:
PO4 - somewhere between .08 and .16
ALK - 11.5
Ca - 440
Mg - 1400
Sg - 1.026 - measured with digital and hand held refractometers calibrated against calibration fluid.

I am running Red Sea Coral Pro salt so these numbers are about what is expected. I am dosing the 3 part Red Sea chemicals to keep them up between water changes.

About 2 months ago I switched from a terrible protein skimmer to a Bubble King dual cone 180. It pulls more garbage in a day than my old one did in a week and a half. I have also been dosing Red Sea Reef energy as the nitrates were coming down.

I got rid of all my macro algae a while ago because I switched sumps and haven't got the space for it anymore. All the research I did suggested there wasn't enough of it there to do much anyway. I have not seen any difference in anything I can test for, so it seems like it wasn't doing much.

There is something odd though. I have a Blue Echinata, Purple Stylo, and Pink Birdsnest that seem to be growing still, though not fast. I just don't get what would be causing the Staghorn and Monti to die off since they are supposed to be some of the hardiest SPS's out there.

[bobssecrtsn]

how big is your system? if its something >60 gallons you might have p04 and n03 dropped to fast?

[camaroguy]

Its a 125 gallon tank and roughly 30 gallon sump.

P04 hasn't really changed at all to be honest. Just NO3 was brought down over months. I suppose it still could have been too fast?

The effects on these two corals is far more recent though. It has been within the past month or two. Is it possible for a skimmer to be removing something else they were using for energy? This was the reason I started feeding the Reef Energy in the first place, just in case.

[camaroguy]

Any other thoughts on this? Should I just stay the current course and see what happens?

[bobssecrtsn]

Do you skim wet or dry? some say skimmers remove DOCs which are food for corals, and if your saying it skims alot better, well, you can starve your corals that way. do you turn off your skimmer at night?

have you checked for pest? acro crabs? bristol worms eating acros?

[danrobberg]

Are you supposed to turn your skimmer off at night?

[ycnibrc]

check your K potassium level if it's in the low 300 then bring it back close to 400 which is sea level. Montipora do much better when K is close to sea level.