SPS bleaching after 5-6 years of success

[slow_leak]

I am writing to get help on my tank concerning a recent bleaching trend of SPS corals. I have had very good success until recently. The bleaching pattern is on the base of 12" tall colonies and spreading everyday further up.

The tank is 140 gallon 28" tall and 2'X4'wide. It contains a variety of corals. Some colonies upto 6 years old. SPS are place on the top less than 16" from surface.

Lighting is AQ 2X250W HQI AQ 10K bulbs and 1X150W HQI AQ 20K bulb. I use ER CS 8" Diameter skimmer about 24" tall / Self made reactor / Tunze Osmolator / Two Tunze Stream pumps. 40 cc of near saturated lime water is added shortly after lights go out to reduce phosphate and increase Ca & Alk.

As of this week water quality is as follows:

Temperature 75c - TECO Chiller (will double check temp manually in AM) felt in normal range
Salinity 1.025 by refractomer and hydrometer
Alkalinity - 200-210 ppm CaCO3 (LaMotte)
Calcium - About 450-500 pm Ca (LaMotte)
Magnesium - 1300 ppm (Salifert)
pH not measured

Nutrient Levels PO4 / NO3 are unknown. Diatom, algae growth is slow. I will check with Hach Method for phosphate on Monday as I have access to a DR/2000. It has always been <0.1ppm in the past so I have not changed husbandry and have abandoned the repetitive test. Chateomorpha growing indicating some nitrate is present being place in acrylic separation acclimation chamber.

Other factors are I traded in over grown SPS at local store for an assortment of 10-15 frags in last month. I also started using carbon during the upgrade - TLF brand.

The bleaching is always from the base up except for what was told was an encrusting brown monti I have had 5-6 years. I have broken off a bleach fragment on this coral but did not see anysigns of AEFW from last batch of frags. It is not conclusive but I did use a magnifying glass carefully. I did find 2 copepods though. I have not added new fish / frags in prior 8-12 months.

Plan of action sto reverse bleaching-
--------------------------------------------------------------------------
grow chateo faster on 20 gallon sump with 16 hr/day 130 watt C bulbs to remove unbound phosphate

consider using Salifert Flastworm Exit for AEFW Individual freshwater dipping seeming silly since eggs will be everywhere. I looked with a flash light at night and can not find anything resembling the many prior posts showing AEFW.


Any other suggestions besides punting the ball????

[just dave]

IME this can happen when colonies get bigger as light and water flow to the bases becomes restricted, However, this does not sound like what you are seeing as its rate of decline is rather fast.

I've seen iron based phosphate removers do this when added to a system.

AEFW as you've already found out but they don't cause bleaching.
They are eating the tissue though when infected you may notice a overall paling of the coral at first.

[Amphiprion]

Why have you not been checking pH. It may help to know the day-to-day fluctuation in case that could potentially be the problem.

[Sk8r]

And how old are your lights? Has there been any change in your water supply?

[carib]

temp. swing?kh swing?nitrate?x-or-y toxic level.BIG POSIBILITY-Temperature 75c - TECO

[orientalexpress]

tell me u didn't change salt?what kind of salt u been using?gl



lapsan

[carpus]

i know you mentioned you check the bleached parts that broke off.... but i notice a base up bleaching trend when my tank was infested with red bugs. I dont think red bugs hang out on bleached parts. And plus you traded in some frags... might have came with some frags?

i dunno.

[slow_leak]

The temp is stable from the controller/heater built in the chiller. Marine Monolith used to sell them from Italy.

Anyway...

continuous ph meter $100
nitrate test $45
2X250 AQ HQI DE 1$80

I did not change salts. I use IO always.

The changes I can see are adding carbon, trading in larger specimens for frags. Decline may be unrelated.

One observation is that the rocks are getting a green tint to them instead of the coraline algae. I'll do nitrates immediately.

I replaced a 150 DE 20k 2-3 months ago. Its time to replace the other bulbs.

All the suggestions are good. AEFW would not wipe out tank, just about 1/3 to 1/2.

[ObscurityKnocks]

I have heard adding carbon after long periods of not using it could rapidly increase water clarity causing more light penetration which can cause bleaching.

[29reef]

Im thinking its something that the carbon has removed from your water that is the problem or the cause anyway. Sounds like an awsome tank that has been setup properly and maintained well. One other thing is that there may be some sort of lack in nutrients and the corals are not to happy with this..zeovit syndrome is what i deem it... seems like with all this negitave press nutrients are getting lately people are removing too many of them causing their corals to slowly lighten and "color up" but then decline into poor health. How fast are the tissues dissapearing is it a slow thing over a week or two or something over night..the fact that you found copepods on the dead acro makes me think that this is not a predator because the pod is just there for clean up post mort. My plan of acton would be to get that carbon out of the water and hold off on a water change for a few weeks. Do you add any supplements like iron magnesium or AA's?

[slow_leak]

It seems that tanks will delicate acros are very suspetible to change after years of have the same conditions. It has occured that nutrients are lacking. After some thought I may loose a few colonies but should be OK.

Now that I think about it I did add purigen and carbon at the same time without use carbon for many months. I did not se humis in the water but that is meaningless observation. It could be phosphate leach in carbon too.

I did add iron for the macros in the past . Have stopped. It is probably all oxidized in 1-2 days in aerated water with actinic lights.

I took out the carbon and will feed more, over next few weeks. Nitrates and phosphates will be checked when new test kits arrive.

The tank was setup well. The osmolator makes things very easy. I couldn't think of much to upgrade except I would prefer two 54W T5's instead of the 150 DE 20K.

Well I did bite the bullet and spent all the money to test the missing parts except the ph meter.

As far as tank health, I may sound crazy but can predict the N/K limitation by looking at the trace algae growing. Trace red cyano growing on the rocks indicates nitrates are limiting. Cyano can be irradicated with adding sodium nitrate to dosages at 3-5 ppm in water max.

By the way my garden took a pounding this weekend too. We had hard pea sized hail for 20 minutes and the peppers/tomatoes/ect look like frozen spinach. Weird weather- Hot and sunny all day otherwise.

[Horace]

I would bet money its the Carbon.....I have seen and heard about this before. How are you useing the carbon? If you introduce carbon too fast you almost certainly WILL have tissue loss. If you are running the carbon through a reactor that makes the situation even worse. I advise against running carbon "actively" in a reactor because you will strip out stuff so fast that the corals will suffer from shock. If you run carbon, put like 1 cup/100g in a bag and put it in a med flow part of your sump. Do NOT have it in a place that it will get constantly blasted or where water is forced through the bag. Though carbon can help alot, it can also hurt alot if your not careful. Thankfully I have not had this happen to me, but my buddy up the street did....I learned from his mistake!

[DitchPlains2]

Also too, sometimes a kalk slurry like you said can be detrimental, have you thought of doing a drip? could be safer and less detrimental to your corals and fish. I suspect it is the carbon, carbon can drop Ph significantly, and also too, it will strip your tank of nurtients, but even worse carbon particles can infiltrate the tank and small polyped corals will often eat and consume the tiny particles and thus tissue death. Just what I noticed in my own tank, my corals often seemed harmed after adding carbon and carbon particles floating around my tank. I don't use carbon, I run seachems phosguard in a reactor. It doesn't effect Ph which is good. just my two cents, sorry to hear such long lived corals are dying, maybe frag them before you loose the entire colony. sotp using carbon, do some water changes, and maybe run ozone. Ozone can prevent RTN and DTN.'

cheers
David

[slow_leak]

Carbon / Purigen was semi - passively in the sump in a partition to remove bubbles. A cup of carbon was run in roughly 180 gallons of water.

I did not run kalk slurry, just saturated solution that has settled from most particulate. The aqua medic doser runs 1 min -25cc per day so its contribution is to try and limit phosphate through precipitation.

I'll have to look into Ozone for rtn and dtn. I did not know that . There is a 3 part article in reefkeeping.com. Did it mention this?

[slow_leak]

The Sprung Vol 3 book recommends using carbon continuous or not at all. I would tend to agree with this.