Acropora fading over 10 days, long sweepers

[SPS2020]

Hi all,

A shot in the dark here to see if someone has had a similar issue. Tank is two years old and Acropora have been happy overall. Until...about two weeks ago, I started noticing less PE and color. Sent an ICP test last week, results today all look good except Boron and Iodine are low. The tank has always had zero NO3 and PO4. Immediately, I think "raise the levels". So, I have been adding NO3 over the past week and levels are around 2ppm. PO4 is still at zero, but feeding pellets heavily in effort to raise that as well. Have also ordered AF PO4+. The tank is pretty stable with little fluctuation of anything measurable. One would think the low nutrient levels might be the culprit, but things have been fine for quite a while as a ULNS. Any thoughts are appreciated!

Tank: 100g bare bottom, about 15g in the sump

Lighting: hasn't changed - 4 Hydra 32HD (saxxby), 4 T5 blue plus and actinic at 40%

Dosing:
Part C
Alk
Ca
Mg

RedSea AB+ (20ml per week, very low dose)
RedSea Iodine (two drops per week...need to increase that based upon ICP)

Today:
Salinity 35
Temp 78-80 (daily)
Alk 8.53
Ca 456
Mg 1327
NO3 1.4
PO4 0


Long sweepers and closed polyps

JF Frankie pale and almost burned tips

Miss Scarlett very pale, no PE, long sweepers and seemingly burned tips

 

[kenchilada]

"Feed more" is my first reaction

 

[Yanir34]

What is your Ph reading ?
Are dosing any carbon source?
stop dosing Amino acids !
are you dosing any bacteria in a bottle?

 

[Crustaceon]

I'm in the "feed more" camp on this one. I hate adding nitrates and phosphates. IME, it always ends in coral brown-out because I think it overfeeds zooxanthellae and pretty much any other pest that was being starved out by a lack of nutrients. Feeding your fish extra is a slower way to get to your desired numbers, but IMO it's a MUCH safer and more hassle-free way of doing it. If your your corals are starving now, the last thing you want to do is add a bunch of nutrients and have zooxanthellae bloom within coral tissue. That'll starve corals even more. And that's way too easy to do when you manually dose N&P. Even if you dose a tiny amount of N&P daily to safely raise those parameters, you could have just fed your fish more and had the same result but with a more natural N&P ratio created. Also, a good move and the most impactful thing to do right now would be to allow alk to fall to around 7 dkh.

 

[Oregon Grown Reef]

Fading corals at the top of the tank could mean too much light. Try moving them down if you can. I carbon dose and have heard that lowering dKh would be needed for these systems. Not sure if you're doing that. I didn't believe it until my corals started looking bad with a couple of them showing RTN. I lowered my lights, moved the coral to a lower flow/light area, and started letting the dKh fall. No further tissue loss and the polyps are out again on most of the sps.

Also, did you change your flow schedule recently?

 

[SPS2020]

What is your Ph reading ?

8.1

Are dosing any carbon source?

no

stop dosing Amino acids !

why?

are you dosing any bacteria in a bottle?

no

 

[SPS2020]

Fading corals at the top of the tank could mean too much light. Try moving them down if you can. I carbon dose and have heard that lowering dKh would be needed for these systems. Not sure if you're doing that. I didn't believe it until my corals started looking bad with a couple of them showing RTN. I lowered my lights, moved the coral to a lower flow/light area, and started letting the dKh fall. No further tissue loss and the polyps are out again on most of the sps.

Also, did you change your flow schedule recently?

No chance of moving anything; everything has encrusted that's up top.

No flow change.

 

[SPS2020]

Thanks for everyone's input!!!

 

[Dburr1014]

Any new additions to the tank?
Just throwing that out there along what others have mentioned.
Sweepers mean protect myself.
Do you run carbon?

 

[SPS2020]

Any new additions to the tank?
Just throwing that out there along what others have mentioned.
Sweepers mean protect myself.
Do you run carbon?

No new additions, good question.

"Sweepers mean protect myself." - thank you

I do run Rox 0.8 carbon 24\7 and change monthly

UV Sterilizer 50w inline sump to DT
ATS to keep GHA out of DT. This was a brief problem earlier in the year. Manual removal and spot treat with peroxide, worked well.
Seven fish, all Acro except one Stylo and some zoas on the bare bottom.

 

[SPS2020]

Today: 10 gallon water exchange (DOS).

As of this evening:

Turned off T5 bulbs (described above). Hopefully, will address any further tip damage.
Will feed frozen (reef frenzy) and pellet more often. Usually a piece of nori per day (2 tangs).
No NO3 (chemical) addition. Although, this was not the issue; I started dosing this after the issue began.

Tomorrow: another 10 gallon manual water change (water out, water in). These are a precaution to be sure no contaminants have been introduced.

 

[spsick]

Sounds too clean for the amount of light you have. How much PAR are they receiving?

I feel like just the T5 would be enough light for the system right now.

Just don’t take too much action at once. Feeding more is the safest route right now.

 

[SPS2020]

Sounds too clean for the amount of light you have. How much PAR are they receiving?

I feel like just the T5 would be enough light for the system right now.

Just don’t take too much action at once. Feeding more is the safest route right now.

PAR (prior to turning off T5's earlier today) ranged from mid 400's to 250 down low...nothing crazy. Ironic as things were doing fine with that PAR and ULNS (not intentional).

Stopping chemicals and feed more. I hate changing more than one variable at once!

 

[ScottB]

I hear you on not pulling too many levers at the same time.

Are you getting 0 PO4 with a Hanna ULR? If so, that is where I would start. If you don't want to dose, feed OFTEN. Nori is a good source of phosphates. Pellets generally are as well.

 

[SPS2020]

I hear you on not pulling too many levers at the same time.

Are you getting 0 PO4 with a Hanna ULR? If so, that is where I would start. If you don't want to dose, feed OFTEN. Nori is a good source of phosphates. Pellets generally are as well.

Yes, 0ppm on Hanna ULR Phosphorous Checker. I've upped the feeding quite a bit (Hikari pellet, Reef Frenzy and nori). I didn't check levels yesterday but going to do so later today. There's turf algae growing all over in the tank...no huge amounts, but "sprigs" everywhere. So, I would assume there is some PO4 in the tank.

 

[92Miata]

I hear you on not pulling too many levers at the same time.

Are you getting 0 PO4 with a Hanna ULR? If so, that is where I would start. If you don't want to dose, feed OFTEN. Nori is a good source of phosphates. Pellets generally are as well.

Just want to caveat this - I've seen clear phosphate deprivation signs in my tank at .01-.02 on a ULR hanna. Don't assume that you need 0 on the meter to have issues. These meters aren't perfect. Use the meter to confirm that you understand coral symptoms, but don't take it as gospel.

Bringing levels up to .04-.05 is pretty low risk, and if things look better, you've confirmed your problem.

@SPS2020 - the paleness, messenterial filaments, and burned tips all point to PO4 issues for me. Get some phosphate in there. The quicker the better.