SPS starting to STN

[ssick92]

So over the last few weeks all my SPS and a couple other corals have started to STN, and I have no idea why. They have all been in my tank for a few months but have started to go downhill. I'm hoping you guys can help me trouble shoot.

My skimmer broke about a week ago, and I haven't had a chance to get a new one. My old one was a Coralife 65 so it really didn't do much skimming to begin with. However the corals started to STN before the skimmer even broke, so I don't think that was the main cause, but it probably didn't help anything... I have been running GFO and Carbon as well as UV sterilizer for about 6 months.

My tank is a 30g with a 10g sump running 5 T5 bulbs about 10" above the tank. I do a water change about once a month with B-Ionic salt system. Whenever I put new corals in there, they seem to do really great for about 3 months, then start to lose color and soon start to STN...

My parameters are as follows:
Salinity - 1.026
Calcium - 480 (I usually try to keep it at 450 but I think since corals are dying they are using less)
Alk - 10.6 (I usually try to keep at 9.6 but recently has gone up for unkown reasons)
Mg - 1250
Ammona, Nitrate, Phosphate, Nitrite - 0
pH - 8.2

Inhabitants:
A bunch of Zoas - flourishing, tons of color and growth
Alveopora - Doing great, wonderful color and lots of growth
Toadstool - Same as above
Acans - Same as above
Mushrooms - Same as above
2 Rose Bubble Anemones - Same as above
Open Brain Coral - Good color, not much growth
Pinky Dinky Chalice - Good color, not much growth
Red Montipora - Starting to lose color and STN
Birdsnest - Decent amount of STN
Pavona Maldivensis - Almost completely STNd
Tricolor Acro - Most recent addition, still doing great, lots of polyps extension and good color
GSP - Growing like a weed, like normal
Pavona Frondifera - Barely starting to STN, has looked great for about a year
BiColor War Coral - Barely starting to STN, has had great color but not much growth for about a year
Candy Cane Coral - Started to STN a little bit ago, seems to have stopped but isn't recovering well

Fish are uneffected.

I'm really hoping you guys can help me pinpoint my issue. I'm starting to think I should just get a good quality skimmer to rule that out. Also, for the parts of the STNing corals that are still healthy, should I frag them all and toss away the dead skeletons?

 

[BHD]

Hello,

I don't think your skimmer broke for a few days and sps stn because of it. Your skimmer take out bad stuffs before they have a chance to break down into Nitrate and Phosphate. One week of not doing it job won't raise your phosphate and nitrate to the level of stn.

For the sps corals that already stn, if it doesn't stop, you should frag them and glue them again. Hopefully you can save a little bit of it. When you cut them, cut deep into the healthy area. This will give you a tiny bit more chance that it will survive.


Also Candy Cane Coral isn't a SPS. So they can't really stn (someone correct me if I am wrong). Your tank is very small but you have 2 Rose Bubble Anemones in there.. Does anyone of them actually sting other corals nearby?

Sometimes Zoa and other sps will irritate them to cause stn as well if they touch the sps.

 

[ssick92]

Hello,

I don't think your skimmer broke for a few days and sps stn because of it. Your skimmer take out bad stuffs before they have a chance to break down into Nitrate and Phosphate. One week of not doing it job won't raise your phosphate and nitrate to the level of stn.

For the sps corals that already stn, if it doesn't stop, you should frag them and glue them again. Hopefully you can save a little bit of it. When you cut them, cut deep into the healthy area. This will give you a tiny bit more chance that it will survive.


Also Candy Cane Coral isn't a SPS. So they can't really stn (someone correct me if I am wrong). Your tank is very small but you have 2 Rose Bubble Anemones in there.. Does anyone of them actually sting other corals nearby?

Sometimes Zoa and other sps will irritate them to cause stn as well if they touch the sps.

I just fragged as much of the SPS as I could, so we'll see how that goes.

Also, the anemones aren't touching any of the SPS, only the zoas but I don't really care about that since they are growing like crazy anyway.

Also, I don't really know what to call on the candy cane but it's tissue used to reach all the way to its base, but now all the tissue is up towards the top of the skeleton, and they don't really put out their feeders anymore.

 

[tektite]

How often do you change out your GFO? Have you considered pulling it for awhile to see if it is the issue?