Acropora help question

[ckurtt70]

I've had my 150 sps tank set up for 3 yrs now. Many of my acros are doing well, entrusting, getting bigger, decent PE. But a few look a little sickly. They are still growing but the polyps are retracted. At first I chocked it up to alk burn as I have did some struggles keeping it steady but alk burn usually damages the tips. The across in question do not have burnt tips. I've also rules out parasites as far as I can tell. I have a ICP test out for analysis but in the meantime asking for some thought about cause and fix. Thanks!

 

[Tahoe61]

Hi and Welcome to R2R.

What type of lighting?
You have ruled out red and black bugs?

Typical questions about parameters and dosing? N/P....

 

[ckurtt70]

Hi and Welcome to R2R.

What type of lighting?
You have ruled out red and black bugs?

Typical questions about parameters and dosing? N/P....

Led lighting 250-350 Par
PO4 at 0.7 ppm
Alk 7.7
Salinity 1.023
Dosing kalk, all4reef, NP bactobalance
No sign of bugs or aefw

 

[xabo]

Salinity is a little low....raise it to 1.025 - 1.026

 

[bobnicaragua]

It looks like a lot of shadowing in the pics, how’s the light coverage over the tank?

Do you track tank PH or room CO2? The higher I’ve been able to keep my PH and minimize the nightly PH drop, the better my acros have done. Just dosing all kalkwasser at night will make a difference.

 

[ckurtt70]

Salinity is a little low....raise it to 1.025 - 1.026

Yeah this was a surprise. I usually keep it at 1.025 and will raise it back up. These issues started before the salinity drop though.

 

[ckurtt70]

It looks like a lot of shadowing in the pics, how’s the light coverage over the tank?

Do you track tank PH or room CO2? The higher I’ve been able to keep my PH and minimize the nightly PH drop, the better my acros have done. Just dosing all kalkwasser at night will make a difference.

The tank is 48x30x24 and I run 3 hydra 64's and a 48" blade grow. Some shadowing on the edges but not bad.

I use a Hydros controller and kalkwasser to keep the pH between 8.10 and 8.20.

 

[Oldreefer44]

Any predatory fish? If they sense a fish that could eat them they will extend at night to avoid predation.

 

[ckurtt70]

Any predatory fish? If they sense a fish that could eat them they will extend at night to avoid predation.

I've never observed any nipping.

 

[Dburr1014]

How's the flow in the tank, op?

 

[UMALUM]

Not all acros will display heavy pe during the photo period and will sometimes switch their schedule back and forth as they mature. Check the pieces after the lights go out. As someone who's not intimated by phosphate I feel a little funny saying it but unless your number is missing a 0 you got issues that will slowly carch up to you especially running lower alk. and par. If your gonna run higher nutrients you have to compensate.

 

[ckurtt70]

How's the flow in the tank, op?

Two 4K gyres and two Octo pulse 4

 

[ckurtt70]

Not all acros will display heavy pe during the photo period and will sometimes switch their schedule back and forth as they mature. Check the pieces after the lights go out. As someone who's not intimated by phosphate I feel a little funny saying it but unless your number is missing a 0 you got issues that will slowly carch up to you especially running lower alk. and par. If your gonna run higher nutrients you have to compensate.

Yeah that's a typo. PO4 is 0.07 ppm

 

[UMALUM]

Yeah that's a typo. PO4 is 0.07 ppm

Kinda figured

 

[fish_collector]

Your acro issue is what most complain about. I'm a member of a fairly large local club and we've all seen each other's tanks, what I've taken note of is the tanks that have the largest and most successful acro colonies are the ones that strive to maintain stability across the board. Eliminating swings of any kind are critical for long term success. I'm certainly no expert and have many frags that behave as yours do. I'm guilty of tinkering with parameters and expecting to see results the next day and it just isn't going to happen. We as the stewards of our tanks need to make a small change and then step back for perhaps a few weeks to see what change occurs and trust me I'm a hypocrite to even make that kind of statement as I tinker with my tank on a daily basis lol.

Post some follow up if you discover something that makes an improvement.

 

[fish_collector]

I have noticed in my tank that when I go in and harvest a lot of the algae on the glass of wherever, if I don't supplement the nutrients that evening, nitrate and phosphate, that by the end of the photocycle the next day all of my corals will have paled out by a significant degree and PE will suffer as well. I have came to the conclusion that the remaining algae are going into survival mode and stripping the water of available nutrients leaving the corals to starve out. I've pretty much eliminated that scenario by dosing nutrients right after I do any cleaning in the tank. But by solving one problem I've likely created another by causing a nutrient swing, it's an ongoing battle that I need to learn to smooth out the peaks and valleys. I hope that helps.

And by the way it's a bare-bottom lowboy frag tank so it's not always kept clear of algae like a display would be.

 

[Ancient Mariner]

In the early years of my reef I had some acropora frags did well while others were struggling at the same time. Some would just encrust and not branch while others grew branches rapidly. PE in some was great and poor in others. I never could figure out why.

I think as long as you have some acropora doing well I wouldn’t make any wholesale changes. Do play around with positioning to try different light and current levels but sometimes a frag at times behaves poorly for some unknown reason.