Acropora growing, but bleaching along encrustment

[dtruitt]

Both the PC rainbow above, and the TSA Bill Murray below, have been encrusting rapidly and appear to have decent PE. It may be a little bit hard to tell from the photos, but they both have edges which look a little bit grey where they are encrusting.

I've been slowly ramping up the intensity of the whites. 2 or 3 percent a week.

Alk is stable within a margin of error using the salifert test kit. It might swing down a few tenths over a few days here and there, but its close enough whenever I test it that I can't really be sure it's changed at all. Averaging about 10.1dKH

PO4 is 0.1-0.15ppm depending on when I last changed GFO
NO3 is 10-25ppm, depending on feeding.
Ca is 435.
Mg is in the 1400-1500 range, don't really measure it often enough to say exactly where it is no.
Salinity 34.5ppt, stable within 0.5.
Temperature is 78F

Does this look / sound like burnt tips on the encrustment? Garden variety bleaching from increasing par? Pests?

 

[JPHawkins]

A lot of sps new growth is white in color and color up in time. Can’t really see in the pic to really tell much.

 

[dtruitt]

A lot of sps new growth is white in color and color up in time. Can’t really see in the pic to really tell much.

It's like a greyish color. My Milles both lay down an obvious white ring of skeleton well before the flesh catches up, but I hadn't seen this with other species before.

 

[MabuyaQ]

Bring alkalinity down to max 9 but preferably in the 8-8.5 range.

 

[dtruitt]

Bring alkalinity down to max 9 but preferably in the 8-8.5 range.

All my acropora have been healthy at 10.1 for a while. If this is like burnt tips along the encrusting edge, I'm content to wait it out.

Just want to make sure it's not a pest issue, to the best of my knowledge, the tank is AEFW / Red Bug free, but obviously we don't always know before they start causing problems.

 

[ScottB]

All my acropora have been healthy at 10.1 for a while. If this is like burnt tips along the encrusting edge, I'm content to wait it out.

Just want to make sure it's not a pest issue, to the best of my knowledge, the tank is AEFW / Red Bug free, but obviously we don't always know before they start causing problems.

How about an update @dtruitt ?

Also a question about your preference for higher than seawater dkh: what is the method you are following that argues for an alkalinity that is 40% higher than ocean levels?

I know there are at least two salts that mix that high like RS Pro and IORC (which are fine salts) but I am trying to understand this "high" dkh philosophy and where it comes from.

 

[dtruitt]

How about an update @dtruitt ?

Also a question about your preference for higher than seawater dkh: what is the method you are following that argues for an alkalinity that is 40% higher than ocean levels?

I know there are at least two salts that mix that high like RS Pro and IORC (which are fine salts) but I am trying to understand this "high" dkh philosophy and where it comes from.

RS Pro advocates 12.6dKH. That is the salt I use, and I try to get up to 12.6dKH, but cannot maintain much more than 11 right now.

Higher alkalinity and pH means more carbonate relative to bicarbonate in the water. This, both theoretically and anecdotally, allows corals to grow faster since it takes less energy to pull usable carbonate out of the water.

Whenever I increase daily alk supplementation to try to bring the alk up, increased demand usually means it'll plateau a few tenths above where it was before I adjusted the dosage, and then fall back down in a few weeks as everything continues to grow exponentially faster.

The PC Rainbow I posted about did color up on the edge, and the guy I bought my frag from confirmed that he sees a similar grey growth edge.

 

[ScottB]

RS Pro advocates 12.6dKH. That is the salt I use, and I try to get up to 12.6dKH, but cannot maintain much more than 11 right now.

Higher alkalinity and pH means more carbonate relative to bicarbonate in the water. This, both theoretically and anecdotally, allows corals to grow faster since it takes less energy to pull usable carbonate out of the water.

Whenever I increase daily alk supplementation to try to bring the alk up, increased demand usually means it'll plateau a few tenths above where it was before I adjusted the dosage, and then fall back down in a few weeks as everything continues to grow exponentially faster.

The PC Rainbow I posted about did color up on the edge, and the guy I bought my frag from confirmed that he sees a similar grey growth edge.

The Red Sea method seems more popular overseas (from USA) and has a regimen that clearly has some rigorous testing done.

Are you sourcing your acropora from people with a similar methodology? That would probably be helpful for acclimation. I determined my ALK and nutrient targets based on my vendor/supplier parameters and it seems to lower my casualty rates.

Just a thought.

 

[jda]

There is no downside or risk to keeping alk more near 7-8.0. At these levels, then no outside parameter matters at all. I recommend this range. If you want to keep alk up over 10, then you need to keep an eye on a handful of other parameters as well. I keep mine from 6.8 to 7.2... which is close to natural seawater.

 

[dtruitt]

The Red Sea method seems more popular overseas (from USA) and has a regimen that clearly has some rigorous testing done.

Are you sourcing your acropora from people with a similar methodology? That would probably be helpful for acclimation. I determined my ALK and nutrient targets based on my vendor/supplier parameters and it seems to lower my casualty rates.

Just a thought.

I buy 90% of my acropora from a hobbyist that runs what I think is a very nice SPS tank around 8dKH with Radions / T5 hybrid.

I temp acclimate, dip, and mount frags in their forever home with no drip acclimation. I generally see PE after five or ten minutes in the tank.

 

[schuby]

If you think that hobbyist has a very nice SPS tank, then why would you choose to keep your levels different than his?

This is just a comment on your original post. Taking a zoomed out pic and then trying to describe the actual detail is not useful if you want other people's opinion on the root cause of an issue in your tank. The pic you have plus two zoomed in pics, one of each coral, would have been the most useful. A good pic really is worth a thousand words.

When one of my corals is encrusting more, there is a grey/white area around it. Sometimes all the way around and sometimes just in one area. This appears to me to be the coralline dying because the SPS is winning the battle for that space on the rock.

 

[dtruitt]

If you think that hobbyist has a very nice SPS tank, then why would you choose to keep your levels different than his?

This is just a comment on your original post. Taking a zoomed out pic and then trying to describe the actual detail is not useful if you want other people's opinion on the root cause of an issue in your tank. The pic you have plus two zoomed in pics, one of each coral, would have been the most useful. A good pic really is worth a thousand words.

When one of my corals is encrusting more, there is a grey/white area around it. Sometimes all the way around and sometimes just in one area. This appears to me to be the coralline dying because the SPS is winning the battle for that space on the rock.

I'm looking to increase growth since all of the sps in the tank are tiny nubs. 8 dKH works for him, thus far I haven't seen a mortality from stable alk above 10dKH.

It seems that it was just a growth edge, between looking at his mother colony and talking to him the greyish edge is normal for this morph.

Picture from tonight attached. I accidentally knocked it off the rock doing some work in the tank and lost some of the new encrustment.

 

[schuby]

Wow, do I understand nubs! I didn't know such small things were considered frags. They take much longer to start growing than a 1-2 inch frag.

Your frag looks to be doing well.

 

[dtruitt]

Wow, do I understand nubs! I didn't know such small things were considered frags. They take much longer to start growing than a 1-2 inch frag.

Your frag looks to be doing well.

This was a big one. I just picked up a JF Pimped out that's probably half that size. I can't complain given the price, but faster growth is a little more desirable when you're starting from these tiny little chunks.

 

[Charlie’s Frags]

This was a big one. I just picked up a JF Pimped out that's probably half that size. I can't complain given the price, but faster growth is a little more desirable when you're starting from these tiny little chunks.

Here’s my Pimped out Tenuis

 

[dtruitt]

Here’s my Pimped out Tenuis

Thats terrific growth.

This is what I'm starting with. Color is okay right now, this one definitely looks it's best under heavier blue lights (at least, to my eye).

 

[X-37B]

Alot of people want right now growth. Honestly, it does not work that way.
Patience, stabilty, and close to NSW levels have always worked for me.
I get great growth at 7-7.5 alk.
Never really understood the high alk method but thats just me.
White growth is typically new growth in my tank.
Here is a pic I just took of a stags current new growth.
Check out my build thread as this tank is almost 1.5 years old and has steady growth all along.
Growth has really kicked in since changing from T5's to halides with no other changes.
Right above the stag is a WD that was a pencil eraser in size when I put it in a year ago.