Help, corals bleaching from the base up.

[jayare]

Hello all,
I have had several corals start bleaching in the past weeks. All of these corals were growing and doing great for 4-5 months, and then suddenly started to bleach. I have around 30 sps in my tanks, and many of them still look great, but a few are bleaching from the base up. What could be causing this? Here are tank levels:

pH: 8.0 - 8.3
Alk: 9
Calcium: 400 (this is a little low)
Temp: 79
Salinity: 1.026

Any ideas or suggeestions would be appreciated.

Couple of other things. Last monday I came home to find my true percula dying. He was swimming upside down and what not, so I removed him. All other fish have been fine. Also, I haven't seen my peppermint shrimp in a month, so I'm guessing he's dead. Could an ammonia spike have killed the percula and in turn caused the sps to stress and bleach?

Should I cut the bleaching corals, or just hope they recover?
Thanks,
Jesse

 

[jayare]

bump

 

[zapata41]

are you sure it is not STN'ing from the base up. i have a A.Nana that does this if i dont give it enough flow. it came in from the lfs straight outa the ocean and requires a lot more flow than most of my farmed pieces like or need.

Tim

 

[jayare]

I wouldn't think so. These frags have been in my system since December of '05, so I would think that if it was growing well in its current location, that something else must be up. Everything was looking great and grwoing well (some still are) until around 2 weeks ago.

Could an ammonia spike have caused this? I'm thinking about doing a large (5 gallons is large for my 18 gallon tank) to see if that helps.

I bought a second thermometer yesterday to double check my temp, and it fluctuated between 78-79 day and night.

 

[Kip]

sounds more like necrosis than bleaching to me which is usually a water parameter problem or a flow issue. The more my tank matrues and the corals grow in, the more the corals block each other from flow. If you are sure it isnt a flow issue, then look into some of your tank readings. If you had a NH3 spike, my bet is that would cause some ill-effects.

 

[zapata41]

well since it has taken some many months for this to show up then i am gonna say it again, STN from the base up. if it was a parameter problem then you would have it on other corals and also just wouldnt be from the base up. try crankin up the flow.

Tim

 

[jayare]

Intresting. I can't up the flow. Tank is too small, can't fit any more powerheads, overflow won't handle anymore than what it is currently. Funny thing is, all of these sps that are being effected grew onto the rocks (not glued). So the base was growing at one point.

 

[dwillingm]

I would keep an eye on the coral and if the bleaching or STN continues, frag the healthy pieces about a half inch or so above the dead tissue line.

I had a similar issue with my green slimer, which was on the bottom of my tank. I am pretty sure the problem was lack of flow in the bottom of the tank, (no other acropora in the middle and top of tank have problems) and I am going to add some seio pumps this weekend.

 

[jayare]

I'll check my pumps to see if they've become clogged or flow had been restricted.

 

[twon8]

what types of sps?
if only acros you might want to check for aefw.

 

[jayare]

Milli, table acro, few others

 

[jbundas]

I'm having a similar problem. The tank was doing great for months then starting about a month or so ago, the growth seemed to slow down and the few small bird's nest pieces I had started slowly dying from the base up. Whatever part of the colony that hadn't died yet looked great though - good color and polyps. I'm starting to notice it in a few of the acros as well. Where the bulk of the colony has great color and hugh polyps, but where it had been encrusting around the rock it's on, the tissue starts to fade in color then recede.

So far it seems to be isolated to a few smaller acros (2" or less) in one area of the tank which happens to have the lowest flow. Larger colonies and everything everywhere else looks smokin awesome.

Another oddity I have is monti caps with pale tissue but good polyps. That's always been the case in my tank but they were doing much better in the 6-8 months after the complete rebuild.

All my numbers are right on and stay very stable. I also replace the cartriges in my RO recently and did a few large water changes with no effect. I'm going to try increase flow in general and increasing the feeding.

My tank is absolutely spotless as far as algea goes. I don't even scrape the glass anymore except to remove coraline. The EV240 that's on this 75g system has a ton of bubbles in the cylinder but hardly produces any gunk in the cup anymore. Bio load is pretty low in general - only recently up to 4 fish which I used to only feed like 2-3 times a week.

I'm thinking that after the tank rebuild, the new liverock had lots of available nutrients which have been slowly depleted over the months. The tank is heavily stocked with sps, and I think there's just not enough gub to go around anymore. Seems to make sense that if a colony looks healthly but stops encrusting and starts to sacrifice it's recently aquired realestate that's in the low light/low flow areas around the base, that it's just trying to support the parts that are producing the most energy from light and polyps out in the good flow.

So far I haven't seen any signs of worms or bugs so I'm just going to keep feeding more and watch.

 

[jayare]

I'm starting to wondering if under-feeding my tank has lead to this. I started cutting back feedings due to an increase in various macro algaes. I plan to increase feeding.

 

[jbundas]

I did the same thing on my previous setup. It was also mostly sps but had what I would consider a significant pest algae problem. That's when I got into the habit of minimizing feeding the 2 fish that were in there. Once the corals started to look bad, I started target feeding after the lights went out. That seemed to help the corals but it was still a battle for the nutrients between them and the more quickly spreading algae.....so I gutted the tank and replaced the rock/substrate - also a move to get rid of the rouge mushrooms and zoanthids.

Currently, I feed the fish once a day with a variety of frozen stuff. If I'm up late enough, I'll dump in either some golden pearls or cyclopese after the lights are out. In the morning, I'll throw in which ever one I didn't do the previous night. So far so good. Having clean liverock and a fuge full of cheato makes it much easier for the tank to handle heavy feedings.

 

[jiggy]

could it be growth? (base encrusting)

 

[jayare]

Doubt if its growth. It was growing nicely onto the rock, but seems to be bleaching in the opposite direction

 

[prop-frags]

Any chance you can show us a pic or two?
How often are you doing water changes? What kind of additives are you putting in? All kinds of crazy stuff can happen fast in a system of that size. Are you testing your water parms? Can you give us a run-down of the current levels you are testing for?

 

[kj5432]

Generally SPS corals do not "bleach" from the base up. It would most likely be RTN or STN.