Corals bleaching, could use some help


New member
My tank has been up since the beginning of December 2012 and in the past few weeks I have had a few pieces of coral bleach out and I can't figure it out. So lets start out with equipment and parameters:

34 gal solana
Tunze Osmolator
Tunze 9002 skimmer
AI sol blue (10" above water)
carbon and GFO for chemical filtration
sponge replaced daily, filter pad replaced 2-3x per week

Water parameters are fairly stable at
7.5 dKH
425 ppm Ca
1300 ppm Mg
5 ppm nitrate
0 ppm Phosphate (via Salifert)

Water changes are 5 gallons weekly

Lighting schedule
(Time start/W/B/RB/ramp)

My temp has been at 82 for maybe a week or two, the thermostat on my heater is busted, and I am getting an APex JR tomorrow to keep temp at 80F.

OK, so finally we get to the problem. Some stuff is thriving and some is bleaching and I cannot figure it out. I have 4 chalices low in the tank in very similar lighting and flow conditions, 3 look great, one is bleaching. I have 5 montis in similar light/flow. Monti cap is unbelievably bright, chili pepper is fantastic, sunset is great, undata is growing, but very poor coloration, rainbow monti is only rainbow in the sense that white can be said to contain all colors. Frogspawn is fantastic, went from one head to 2.5 in a few months, the golden torch 3 inches away looked great and has bleached over the last week. Magicians palys are great, blue palys are losing color.

You get the point, many corals are great while closely related corals in similar conditions are doing poorly.

Other corals that are thriving include duncans, favia, mushrooms, pavona, GSP, xenia.

My livestock includes a yellow watchman goby (that I have not seen for a month since he was rescued from the overflow, a mandarin dragonette (eats frozen food like a pig), a tube anemone, and maxima clam.

Any ideas? My only thoughts are temp was too high for a week or two, or my lighting schedule is no good...


New member
82 shouldn't be much of a problem. I don't know how sensitive the Salifert test is, but too little phosphate can lead to bleaching.

Do you have any algae growth?

Nano sapiens

New member
Various corals, even closely related ones, can have difference tolerances for either rapid temp swings and/or high/low temp extremes. On reefs that experience somewhat higher temps than normal, one can find corals with their natural coloration right next to bleached specimens.

If corals that are used to lower temp (say 77 or so) are rapidly exposed to lower /mid 80s, then partial or total bleaching of some corals would not be unexpected. I suspect that is what you have going on here and that would explain why only a few species/types are effected. Often, these bleached corals can reacquire/repopulate the zooanthellae, but it can take quite a while for full recovery. As long as the flesh is still firm and intact they have a good chance to come back. Keep them well fed since they will rely more on nutrients until the zooanthellae are back in full force.


New member
I have absolutely no algae growth (apart from coralline). I wonder if I am starving the tank as I do try to be very light on feeding. I will try to spot feed a little bit more and see if that helps sustain the healthy corals and possibly help the worse off ones to recover. I have Hikari plankton, mysis, and spirulina brine, reef nutrition oyster feast, and cyclopeeze.

I hope to add another fish soon as well. The extra feeding should add some more nutrients to the tank if it is indeed being starved.

I don't think there are really rapid temp swings, just temperature is a degree or two above what I would like it. The controller should help to get that dialed in rock solid and allow me to monitor temp fluctuations as well.

Thanks everyone for the input so far. Would love to hear some opinions on my light schedule as well. I am new to LEDs and have only been using them since decmber

Nano sapiens

New member
If you were starving your corals then the vast majority would first be pale, not bleached, before they start loosing tissue. Bleached is when they go white since all the zooanthellae are expelled, which usually happens quickly due to an event such as high temps. Pale coloration is much more gradual and the corals will look 'pastel' in coloration.

Try to post some pics so that people can see what is going on.


New member
A photo would definitely help to see the extent of the problem. As for the cause I am hesitant to believe that it was the temperature, 82 just isn't high enough to cause our zooxanthellate corals much harm imho. And an appropriately sized heater will not be able to raise tank temperatures quickly enough to qualify as "rapid change".

I can just say that I have seen this bleaching in lots of newish tanks with very low nutrients. People don't notice it at first because the corals' colors actually improve for a time, only to then fade away slowly. The next step after that is slow tissue loss.

I would start feeding more and see if the situation improves - you will not harm your tank if you feed more heavily for a few weeks or until you get measurable PO4. If you get some algae growth so be it - it's a small price for saving your corals and your cleanup crew should be starved enough to mow it down. ;)

As for the lighting: the schedule looks okay to me, but I can't say anything about the fixture and its spectrum.


Go Spurs Go!!!
Premium Member
Does the SOL have the stock 40 and 70 degree lenses? If so then changing to all 70 degree lenses will help. 40 degree op-tics on a small tank can cook one coral and not effect the one right next to it.


New member
One additional thought - if it is the lack of phosphate (because I just read the first post again and saw that akirsonis is using GFO). I would remove the GFO for a while and see if that gets you an improvement.


New member
It might be more accurate to say the most affected corals are "pale", they are not totally bleached and 100% white. For example my favites looked a little pale one day, then more so and more so and lost probably 80% of its coloration within about 5-6 days of the initial loss. I will be gone all day tomorrow but should be able to get some pictures up on Wednesday.

I have been spot feeding a bunch and will monitor everything over the next few weeks. I will also pause use of GFO for the next couple of weeks to see how that helps.

Yes, the sol does have stock 40 degree optics and I have been considering changing those to 70s for a while. I will look into those and probably place an order very soon.

Thanks for all the help everyone!