SPS bleaching problem

[mark97r6]

Hey guys,

Gotta confirm my readings so bare with me there but i am having a little trouble with my SPS corals.

We had a bit of a heat wave (yes the UK occasionally gets warm!) a month or so ago and i lost 3 large 13"+ colonies!!
I was gutted but just put it down to the heat as the tank got to 85! I normally run 77-80. The really hot weather was less than a week and hit us by surprise.

There was no loss of colour they just bleached from the base up, and frags couldnt be saved from the parent colonies (all various acros BTW)
I have just had a A.millipora start with the same simtoms. No tissue recession no colour loss just very fast bleaching from the base up. The temp is under control, i took frags and these have suffored the same fate as the parent colony. Taking about a week all in all to bleach.
This milli has been in my tank in the same place for about 14 months.

I struggle to keep my calcium up and a reactor is on the list, would low/fluctuating calcium give these symtoms?
Is there an obvious problem with the specific bleaching?

I was thinking pests, but after trawling through old threads these all suggest colour loss first. Can i rule these out? I do have a coral beauty that i suspect may have started nipping a little. He is going either way just in case.

Thanks for any help youu guys can offer.
Mark

 

[iCam]

I don't really understand how they are bleaching, but without color loss.

Fluctuating/low calcium itself probably isn't harmful, but can be an indicator of other parameters that might be off (alkalinity, et cetera).

 

[Wiskey]

Is it RTN? Tissue flaking off?

How is your alk? Do you struggle to keep that up too?

IMHO Alk is far more important than CA and if the ALK is low this sort of thing could happen.

Whiskey

 

[jjjimmy]

If some of your colonies are that big, you may have a bit of a flow problem. As corals grow they tend to block off flow to other corals or even themselves.

 

[mark97r6]

Thanks for all the advice guys.

Too be honest i started a new job about 5months or so ago, so the tank hasnt been a priority and has been a little neglected.

I really need to get everything tested a see where i stand, it could be something obvious! I just see this strange patten of bleaching and wondered if there was a obvious cause from that.

I havent struggled with my alk in the past, though it is overdue for a check. My calcium has only started struggleing as my corals have started growing bigger, and like i said a reactor is on the shopping list.

Flow was my first thought! i thought the center of the colonies must be struggling for good water movement so i added a couple more 6100 streams about 6wks ago (giving me 5 6100's).
This took my tank turnover from 35x to a little over 50x per hour.

There are some large colonies but only what was transfered from my last tank, the majority are frags. The tank is 8' 360g.

RTN, although i am familier with the condition i am not sure how to identify it! Will look into this. The tissue doesnt so much flake off as just recides, doesnt seem to go anywhere.
I will get a pic of the milli tomorrow when my lights are back on. The coral is still a stunning red withreally good PE. though recedingg really really fast.

Would/could low alk have these types of affects?
Can i rule out pests? everything i come across regarding pests seems to point towards colour loss!
What about the angel? could being picked at cause bleaching in this way?

Thanks guys keep it coming and i will snap some pics and test.

Regards
Mark

 

[b0wenj]

This may have nothing to do with your problem, but I am wondering have you replaced your lights recently? Also what kind of lights do you use?

 

[dreaminmel]

From what I understand bleaching is where the tissue remains, just loses color. Tissue recession can occur due to pests, water quality etc with the rest of the coral remaining colorful. If you have corals losing tissue from the base up the first things I'd check would be alkalinity and pests. Are the spots where skeleton is exposed turning green at all?

Also, I'm not suspecting the angel as the cause as normally they would only nip at and irritate the tips... not the base.

 

[getwood65]

your corals are not bleaching they are suffering from stn and until you fix the problem in your tank(one or more parameters out of whack)this will continue.check all your water parameters and post back.also describe anything else that is happening in your tank-are your corals turning brown?

 

[mark97r6]

Hey guys run some checks. Not as good as i hoped but got a little chicken and egg thing going on!

Temp 77-80
Alk 7.3
pH 8.4
Calcium 220 mg/l
Nitrate 10mg/l
Nitrite 0.1mg/l
Ammonia 0
Phosphate ~1 mg/l

These are all taken from a Hagen test kit,, are they any good? I dont beleve them to be very accurate for phosphates.
Alk is quite low, but lower enough to cause probs?
Calcium is low as i suspected. The nitrate is quite alarming, though could this be the dead tissue polluting the water?
Is the temp swinging to much?

Anything else you would have me test that could explain?
I usually test magnesium also but my test kit has run out.

Heres a pic of the milli

Is the Alk my problem? STN?

All corals are holding good colour, nothing else at all seems out of place. This is exzactly what happened to my others when i blamed the hot spell.

Thanks alot for this help it is really appreciated.
Mark

 

[mark97r6]

Sorry lights! I run 2 x 250w and 2 x 400w lowbay halides plus 4 x 55w actinic PC supplement.
The halide bulbs were changed about 3months ago from 10k to 20k bulbs.

 

[Horace]

That is Definitely STN. The tissue is erroding not bleaching. What your seeing is pure white skeleton with no tissue . This is very likely related to either a major swing in Alk, and could be a result of a large temp swing as well if your corals never see temps of 85 degrees. A 5 degree increase of temp over your normal high of 80 could very well be the reason IMO. None of yoru parameters are so far out of line that they would cause TN IMO. And alk of 7.3 is not super low either. That is in the acceptable range of 7.0 - 8.0 that natural salt water falls under. IMO you should start doing some good size water changes just to be sure its not some polutant.

Also note, STN usually occurs a week to two weeks after the event which caused it.

 

[Horace]

Now that I look at that picture again.. there is some green at the base of your coral as well. That is caused by high phosphates and will cause TN as well.....So it looks like you have a nutrient problem as well to me.

 

[mark97r6]

Thanks Kurt.
large water changes it is then. Would adding carbon be of any use, or is this just changes things again so best overlooked? This may still be happining because of the large temp increase then, or maybe pollutants in the water from the colonies i lost in this...?

The Alk has dropped, when i was on top of things i kept a constant KH9. Though i cant say how rapidly it fell.

Thanks again guuys, i just hope it stops happining with water changes.
Mark

 

[Wiskey]

That Phosphate is very alarming, so is the Nitrate, I say it is time for some water changes, and crank that skimmer up.

HTH,
Whiskey

 

[slavearm]

Get a bag or two of Rowaphos and dump it in your sump somewhere (use the sock that it comes with). Watch your alk... the Rowa will lower it, but it is better to be safe than sorry. If your PO4 is really that high, that is probably the problem. A good fat waterchange will also help, but given the volume of water, I doubt you are going to be able to make a huge dent with one change.

 

[RichConley]

I wouldnt think alk of 7.4 would be a problem here, unless hes talking about meq/l, which, with Ca at 220, he very well could be.

Is that alk dkH, or meq/l?

 

[mark97r6]

Thanks guys,
I will do what water changes i can this week, add some rowaphos and see what my params are in abot a weeks time, will also get a more accurate PO4 test kit.
the alk reading is dkh.