SPS bleaching

[jpruitt]

Guys I'm not really new to the hobby but I had a question about sps. About one week ago I put a phosphate reactor online with Rowaphos media mixed with rox.8 Carbon. I was having a little bit of hair algae growing around my overflow. 4 days after putting it online around 50 percent of my sps colonies/frags have turned almost completely white. Not rtn just really bleached. Still getiting full polyp extension. Have since pulled the reactor offline and done around 100 gallons worth of water changes with blue bucket Red Sea. Wondering if this is the cause of my issues or something else I am looking over. I did increase my alk during this same time from 8.4 to 8.8 via calcium reactor.

Tank specs.

190 gallon display with 48 gallon sump. 178 gallons total volumn.
Alk 8.7 Hanna
Calcium 440 salifert
Mag 1380 salifert
No3-0 Red Sea.
Po4- unreadable Red Sea kit and Hanna

Any insight would be great. This is my first real go around with a dominant sps tank.

 

[MondoBongo]

i've had this happen with low nutrients to my sps as well.

tank was too clean and most of my sps colonies turned white. i've increased feeding considerably over the last 6 weeks or so, and most of them are starting to regain full color again.

my algae is back to being out of control, but my sps looks way better.

 

[C.Eymann]

Always need to beat careful with sps and phosphate media, that is probably the case here. to be on the safe side though doesn't hurt to double check other possible causes, do run carbon often ? Believe it or not I have heard of people who had not run carbon for long periods of time decide to run it and a few days later their corals started bleaching a bit but it was actually due to light shock, carbon can make a big difference on light penetration/water clarity. Also other things to consider are temperature, also when people run carbon they use a pump to run it in a reactor, that pump, however small will add some heat to the tank, take this increase of temp and the increase of light penetration, will cause photosynthesis to start occurring at a faster rate than the corals are used to, they won't be able to oxidize free radicals that are the by product and will reject zooanxthelle as self preservation.

Im sure in your case it's the significant drop in P04 that caused them to bleach, but just some other things that don't hurt to consider. Like others said feed well and they should color back up soon.

 

[jml1149]

Believe it or not I have heard of people who had not run carbon for long periods of time decide to run it and a few days later their corals started bleaching a bit but it was actually due to light shock, carbon can make a big difference on light penetration/water clarity.

I have seen this in my tank as well, is it possible it's also a light shock issue here too? Or a combination? Perhaps if we turn on the GFO reactor and drop our lights 20%, this might not happen?

 

[C.Eymann]

I have no LED experience but I would imagine dropping LED power % for a few days and ramp back up might not be a bad idea if you only occasionally use carbon.

I would also wager LED lit tanks would be more susceptible to this occurring with carbon use.

 

[C.Eymann]

Further thought into this whole "occasionally running carbon can lead to light shock" is that
carbon can absorb some beneficial things in the water such as some trace elements including iodine. Iodine in particular is utilized by coral in the oxidation process they use to rid their tissues of free radicals caused by photosynthesis. So carbon might be a double punch in a ways to causing light shock or bleaching.

While of course a lot of what I am swaying is in theory, I believe it is fairly scientifically sound.

Would be interested to hear what someone with more bio chemical knowledge thinks about it.

 

[jpruitt]

Thanks for the input guys. This was the first time I ran carbon or Gfo on this tank. Tank is 10 months old. I took the reactor off line and did increase feedings. Took about 3 to 4 days before they started to bleach them the went south very quickly.

 

[C.Eymann]

Thanks for the input guys. This was the first time I ran carbon or Gfo on this tank. Tank is 10 months old. I took the reactor off line and did increase feedings. Took about 3 to 4 days before they started to bleach them the went south very quickly.

I'm suspecting light shock if they seriously started dying, also possibly lack of nutrients though, I see you have 0 phosphate and nitrate, that can cause pale colors and slow decline, but soundlike things went quickly? Also do you run LEDs?

 

[jpruitt]

250 watt halides. Radium 20k


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[C.Eymann]

Hmmm, have had coral loss or just bleaching? Pics?
If you were running LEDs my money would be on light shock, but with a 20k Radium I can't see carbon use/clearer water cause serious bleaching. Who knows though, post some pics.

 

[Scorpius]

Running gfo/carbon especially rox.08 will strip a tank of nutrients in no time in a reactor due to their high efficiency and contact time. Been down this road myself and I will only ever run gfo in a media bag. I don't run carbon, but if I do it will also only be in a media bag.