Duncan sad after holiday, help!

[Jeph]

Hi there! I've been a lurker and procrastinating on my first post here, sad that it had to be a cry for help! :'(

We've had our duncan coral in our 40 gallon reef tank for 3 months and it's been the happiest little trooper, readily receiving artemia when spot-fed, putting out plump tentacles and growing new baby heads... Last week my partner and I went away for 4 days: we had a family member over to housesit with specific instructions (e.g. allocated amounts of artemia feeding, feed the fish pellets first, etc). There was one day when the housesitter noticed that the tank was noisy, and we walked her through the RO water topping up process on the phone. When we returned everyone in the tank looked fine, except for the duncan - it was all limp and retracted. The skeleton has also lost some of the green fluorescence, and looked wrinkled.

I did a 20% water change immediately after we got home (I had done a 10% the week before)... it has since been a full week and it had pretty much stayed retracted and miserable with no improvements the entire week. I did another 20% water change yesterday with KH and Mg dosing, and this morning I think there has been a slight improvement (tentacles a bit further out??) but it is still very limp and unhappy compared to how it was before.

(before)

(after 20% water change upon return, 1 week ago)

(this morning)



We had our water tested at a LFS a week before our trip, and also yesterday (after another 20% water change), and here are the parameters:

1 week before trip:
Salinity: 1.025
pH: 7.9
KH: 7.7
Nh3/4: 0.1
NO2: 0.1
NO3: 8
PO4: 0.2
Calcium: 465
Magnesium: 1108

Yesterday (after another 20% water change):
Salinity: 1.025
pH: 8.0
KH: 7.3
Nh3/4: 0.2
NO2: 0.1
NO3: 11
PO4: 0.2
Calcium: 473
Magnesium: 1125

(Our LFS have advised us to dose up on KH and Mg after water changes, since they seem to be dropping steadily.. we don't have an automatic dosing machine but we are doing it manually)

Current tank inhabitants (tank is over 2 yrs old):
2x Ocellaris clownfish (paired, has zero interest in the Duncan)
2x Pjama Cardinals
1x Rainford Goby
1x Sandsifting starfish
3x hermit crabs (less than 1 inch in size)
4x Astraea snails
+ Codium fragile (macro algae)
+ unaccounted number of bristle worms (have not seen any fireworms so far)

Corals:
1x Duncan
1x Sinularia
1x Toadstool
1x Alveopora (on the other end of tank)
Zoas (5x frags, various)
Fireworks clove polyps (2x frags)
GSP (1x rock)

We can't figure out what's wrong, and any advise or suggestions would be helpful!! Thank you so much

 

[ReefStable]

I would stop feeding it and likely let it do what it needs to do.

If I did anything it would be an iodine dip for possible bacteria problems. But if it's looking a little better, I would let it be to be honest.

Likely whatever happened while you were away (fed something it didn't like, salinity/alk/pH changes, etc) really made it mad and just needs to recover and bounce back.

That's what I would personally do.

 

[moretor1]

i agree on the magnesium the 1100-1200 range is when i definitely saw a lot of sad corals, when raising magnesium i like to dose ~1ml per gallon (fritz mg) every day until it reaches normal levels. After that i typically do 1ml:3gallons once or twice a week to maintain
LPS seem to prefer higher magnesium (1400-1500) anything higher than 1500 might affect inverts and kill them

Do you run any carbon?

What salt are you using? i would've expected higher mg after a 20% wc

 

[jag10016]

water change and coral food!

 

[Matt Bravo]

Gotta boost alk and mag for sure, looks low even before your trip.

 

[Jeph]

Thanks everyone for your advice! Sorry I haven't provided any updates for the past couple months, was hit by a bit of Post-COVID-era work stress

We took the advice given and remedied the Alk & Mg immediately, and it took a couple of weeks for the Duncan to gradually recover to how it was before. We also swapped our default LFS to a couple of different ones that were located farther away, but were more knowledgeable and experienced; we found that their saltwater were more consistent in readings with less swings. We have also invested in the Red Sea Foundation Pro kit - It feels great being able to run the parameters at home anytime we need to.

So yes the Duncan is still alive, kicking, and has grown heaps - We've secured the plug on a rock so it's now above the sand and closer to the light and flow, and it seems to be happy enough to have grown more heads too.