Acro Bleaching From Top Down

[Lago]

Hey everyone I've been starting to try out acros and I was able to get this piece from my work. I had been acclimating it to the light (radion xr15) over the course of a month. After putting it in it's old spot (~300 par) after a week I began to notice just the tops bleaching. So I've moved it down to a ~210 par area (where the picture was taken). I just wanna ask around and see if I made the right call on this? I'm confident it isn't RTN as it's only on the tops of the branches and not on the undersides. Also I still get pretty nice PE on the bleached areas.

(All of these parameters have been stable for the past 2 months and I've had nothing but great growth and color except for the top of this acro. The base still grows. Also the only additive I use in this tank is kalkwasser)

Moved from 300 PAR TO 210 PAR

pH : 8.0-8.2
Alk: 10 - 10.5
PO4: .15
Nitrates: 20
Calcium: 490
Mag: 1600
Iodine: 0.06
Potassium: 410
Iron: .05

Thanks,

 

[christianscorals]

looks like alk burn or temp swings. did the tank it came from have that high of an alkalinity level? haven’t seen any acro react this way toward light to be honest so not sure if that’s your problem

 

[Lago]

looks like alk burn or temp swings. did the tank it came from have that high of an alkalinity level? haven’t seen any acro react this way toward light to be honest so not sure if that’s your problem

Oh thank you for reminding me temp has been at 77.5F-78F (Which there have been no swings of). I'm also not sure if the alk is not my problem because alk burn is essentially coral laying down skeleton faster than flesh can form. So wouldn't that mean there would be no flesh on the tips and I would not be seeing any new polyps in the whitened areas? Also from what I read it seems like burnt tips doesn't seem to discriminate between top and lower halves of branches. So thats where I think light's may be my issue because the only region affected is where it's recieving the most direct light.

The tank it came from was running around 9dkh but nitrates (3.5) and phosphates (0.03) were also pretty low in comparison to my tank. Also if it matters a lot of my corals came from that same tank at work and I had no issues with them (including a staghorn acro)

 

[Tonycass12]

I would be willing to bet that things will improve if you drop your alk to 8-8.5. How stable is you alk?

 

[Lago]

I would be willing to bet that things will improve if you drop your alk to 8-8.5. How stable is you alk?

I'm not sure about changing my entire system for one coral that was doing well and growing prior to be honest with you. Alk doesn't flucuate anymore than .4 dkh per day but I've been keeping alk within just within that 10-10.5 dkh range. Prior (around a month back) it was at 9.7-10.2 dkh. Respectfully, I saw improvements (richer color and growth tips) to all of my corals except this one and I don't believe it is wise to change my entire system for one coral.

 

[christianscorals]

Oh thank you for reminding me temp has been at 77.5F-78F (Which there have been no swings of). I'm also not sure if the alk is not my problem because alk burn is essentially coral laying down skeleton faster than flesh can form. So wouldn't that mean there would be no flesh on the tips and I would not be seeing any new polyps in the whitened areas? Also from what I read it seems like burnt tips doesn't seem to discriminate between top and lower halves of branches. So thats where I think light's may be my issue because the only region affected is where it's recieving the most direct light.

The tank it came from was running around 9dkh but nitrates (3.5) and phosphates (0.03) were also pretty low in comparison to my tank. Also if it matters a lot of my corals came from that same tank at work and I had no issues with them (including a staghorn acro)

pics under blues could help in this situation as well. do you have anything in your tank that could be nipping or eating at it?

 

[Lago]

pics under blues could help in this situation as well. do you have anything in your tank that could be nipping or eating at it?

Nothing comes to mind as for anything picking at the coral I sat and watched to make sure and noticed nothing physically bothering it.

As for the blue lights I'll take a pic of them tomorrow when my lights kick on.

 

[TangerineSpeedo]

This is my theory. In by moving the frag from your work, where the Alk was much lower. The bacteria in this frag's slime coat was compromised. You have plenty of nutrients in your system, but without bacteria to break it down you will have fast growth but alk burn.
OR
You do not have enough flow in this area for the amount of light/alk/nutrients that is hitting this coral.
Are you having visible growth with this frag?

 

[Lago]

This is my theory. In by moving the frag from your work, where the Alk was much lower. The bacteria in this frag's slime coat was compromised. You have plenty of nutrients in your system, but without bacteria to break it down you will have fast growth but alk burn.
OR
You do not have enough flow in this area for the amount of light/alk/nutrients that is hitting this coral.
Are you having visible growth with this frag?

Who knows for sure, just a few things though about your slimecoat idea:

If the slime coat was compromised wouldn't I see similar symptoms on the underside of branches like the top? Secondly, correct me if I'm wrong but alk burn does not spread to previously existing and once colored skeleton towards the base hence the name "burnt tips". That second point of information may be wrong so someone please check that to make sure I'm understanding that right.

Now the flow may very well be possible as I have a gyre on one end of the tank at 100% the coral was 4ft away from the pump (a 4k gyre) but on random flow. But I can't make the randomness between two values like if I want flow to be between 50% and 100% of the pumps power. I was seeing greater growth while light acclimating on the frag rack over the course of a month and since there was no other obstructions I'd be more likely to believe that this may be the case. Now it's in a higher flow area so we can wait and see if the combo of lower light/higher flow end up helping the coral.

 

[Lago]

@christianscorals here's the coral under blue light I know the picture doesn't look great but the tips are darker than some branches.

 

[Lago]

Update: Here we are 2 weeks later, so I'm concluding that it was a lighting issue. Nothing else in the tank has changed (except Alk it's now averaging around 10.5-10.8) and here's the acro now. As you can tell zooxanthellae seems to be recolonizing, especially around the center branch in comparison to the first photo.

 

[sjfishguy]

Alk is way too high. Alk should be around 8. No reason to have it that high.

 

[Lago]

Alk is way too high. Alk should be around 8. No reason to have it that high.

It's for growth, and helping buffer my pH somewhat over winter. Also why shouldn't it be that high the rest of my tank is fine my other acros aren't having issues.