Duncan closed, low Nitrates

[UnnamedReef]

Hey everyone!

First time poster on Reef2Reef, but I used a ton of threads on here to get started. Glad to be a part of the community! I'm very experienced with freshwater tanks, but this is my first saltwater (55 gallon).

My current issue is with my Duncan coral. It closed up a week ago and has not opened since. I've done a bit of looking through threads and others' experiences, so here's what I've got. Looking for any and all (productive) advice!

Tank:
- 2 months old (cycled with empty tank feeding and water changes). Observed ammonia rise, then nitrite, then finally nitrate production. Diatom bloom over the past 2 weeks has largely cleared. Water changes returned levels to close to 0.
- Fluval G3 canister filter (working in a sump within the next few months, waiting for sales and deals)
- Aquamaxx HOB 1.0 skimmer (still in the box, I'm looking to ADD nutrients right now)
- 1.5" sand bed, ~20lbs of live rock and more to add.
- Current occupants are two Ocellaris clownfish, one cardinalfish, my Duncan, and an emerald crab. All appear to be healthy, well colored, and active.
- 1x weekly 20% water change (on hold until nitrates rise)

Numbers:
pH: 8.0
Ammonia: 0
Nitrite: 0
Nitrate: 0
DKH: 8-9, depends on the day
Calcium: 440
Temp: 78 degrees
Regular phytoplankton and zooplankton dosing as well as Reef fusion 1 and 2.

I got this Duncan at Petco not expecting much with two-ish heads and partially open. Within 3 weeks he grew 3 more heads, opened completely every day, and enjoyed mysis shrimp and shrimp pellet target feedings 3x weekly. His skeleton was half green half brown when I got him, and has since filled out with a nice green.

I made a mistake during a water change and didn't add enough salt, so I added directly to the tank. I know now that was a mistake, and the Duncan did not seem pleased. He is roughly in the same spot he's been in where he was successful, but has not re-opened for a week.

I see Duncans are temperamental, and he doesn't LOOK dead or dying to me. Could the direct addition of salt stressed him enough to close for a whole week? I can't target feed with him closed. Could having really low Nitrates make it not worthwhile for him to filter feed, thus staying closed? I'm increasing my feeding amounts and frequencies to try to raise those but as you all know that doesn't happen overnight. Looking for advice, things to try, etc.
Thanks everyone!

Shayne

 

[UnnamedReef]

Also to add: placement is in moderate flow area about 2" off the sand bed. He was placed so his polyps swayed gently in the current. Lighting is two Smatfarm G5s, set to default mixed reef settings and schedules.

 

[Mr. Mojo Rising]

welcome to the reef. The duncan looks like its hanging on, if you can fix whatever is bothering it, it can still come back.

To be honest, we never really know whats going on with the corals, its always a best guess. My best guess here is that your tank being so new is very different from the tank it came from, it might be having a time to acclimate.

Duncan is usually a hardy coral, a good beginner coral. It likes medium light and medium to higher flow.

I also don't see any powerheads listed with your equipment, I feel a return from the canister might not be enough flow for a 50 gallon tank IMO. That size tank needs powerheads.

 

[exnisstech]

To be honest, we never really know whats going on with the corals, its always a best guess.

Unfortunately this is so true. So far I have had Duncan, bubble coral, and frogspawn up an die while another coral of the same type several inches away is thriving. It's frustrating for sure.

 

[UnnamedReef]

Thank you for the reply, I'll get some power heads on order for sure for the far side of the tank. He is closer to the filter return but I definitely see your point. Since he's my only coral i don't mind changing something up to see his reaction. What would you recommend? Add/decrease flow, lower salinity, increase/decrease lighting, none of the above?

 

[Mr. Mojo Rising]

Thank you for the reply, I'll get some power heads on order for sure for the far side of the tank. He is closer to the filter return but I definitely see your point. Since he's my only coral i don't mind changing something up to see his reaction. What would you recommend? Add/decrease flow, lower salinity, increase/decrease lighting, none of the above?

It doesn't look bad, its unhappy, but I see no skeleton, no brown tentacles. I would probably leave it for another week, see what happens.

I think its having a hard time to acclimate to your tank, mostly cause your tank is so new, and I think it will help when you add more flow.

 

[UnnamedReef]

It doesn't look bad, its unhappy, but I see no skeleton, no brown tentacles. I would probably leave it for another week, see what happens.

I think its having a hard time to acclimate to your tank, mostly cause your tank is so new, and I think it will help when you add more flow.

Thank you!! I'll do both of those things. In my other post someone mentioned checking for temperature changes. I'm using a used heater from another tank, and now that I look at the readout on the Fluval the temp has been trending down from 80 to 76.5 now. I'm going to replace it and slowly hike back up to 80 to see what happens. Any recommendations for a power head?

 

[Mr. Mojo Rising]

Thank you!! I'll do both of those things. In my other post someone mentioned checking for temperature changes. I'm using a used heater from another tank, and now that I look at the readout on the Fluval the temp has been trending down from 80 to 76.5 now. I'm going to replace it and slowly hike back up to 80 to see what happens. Any recommendations for a power head?

lol its very hard to recommend a powerhead, you can spend anywhere from $50 up to $500 for a single powerhead. The cheaper ones just shoot continuous stream of water, if you want something that is controllable from your phone, that costs more. It depends how fancy you want it. Using myself as an example, I have 2 gyres in my 40 breeder, which is very much overkill, but thats what I like.

 

[UnnamedReef]

Good to know, thanks! I won't go cheap, but I don't need to be adjusting the flow on my phone either.

 

[radfly]

Leave it alone, stop changing things and be more mindful when changing water.. check the new RO water temp, salinity and kh. Adding salt directly to a tank is really a bad idea.

 

[blecki]

I've always had bad luck with this supposedly 'easy' coral. They always grow well for a bit then waste away suggesting there's some nutrient it needs that's being depleted.

 

[radfly]

It is sensitive to changes, but it is hardy. It is an indicator coral, will tell you when things are off before most other coral, so listen to it.

 

[UnnamedReef]

Thanks everyone, the side head opened slightly yesterday, and the top head is opening slightly today. It seems to be trending in the right direction, and reacts to closing the bottom cabinet. I'll keep an eye on it and update this thread for the next person with Duncan issues.

 

[o2manyfish]

Don't panic over the temperature swing. I have great success with running my 1500g system at 76 during the winter to keep heating costs down. And when the sun does pop up during the winter the tank will swing from 80 to 76 as the sun rises and falls.

Duncans, as mentioned are hardy. When you added the salt directly to the tank if/when the salt crystal undissolved fell onto the tissue they burned it as if I had poured acid on your arm. It might take a few weeks for it to open and be happy.

If your original views of the coral are correct, that it grew 3 new heads in 3 weeks, then your tank was a tank it liked.

Dave B

 

[UnnamedReef]

Dave, thanks for the reply. Definitely made me feel better, I sure as s*** won't be adding salt directly to the tank again.

The duncan continues to open more and more each day, all heads are at least partially open now and the polyps react to food, sound, etc so I think he's on the upswing. Thanks for the help everyone!

 

[JBStuka]

Hey Shayne... welcome to the forums!!! This too is my first post in here. I'm like you with tons of experience in fresh water over the last 30 years and now navigating my way with my first salt tank and trying to learn all of this.

My 70 gallon tank is about 6 months old and I put my first few corals into it about three weeks ago. They sat in a smaller quarantine tank for a few weeks first. My Duncan closed up right away when I moved it into my display tank for about a week and a half... my zoas, hammer, and others.... all did the same thing. They all seemed to be fairly happy in the small tank and I was super concerned my water parameters or lighting were off or something was really making them unhappy. And I was using the same lighting on the small tank and even doing water changes off of the display tank into the quarantine tank.

I bought a new set of power heads and played with the flow and that seemed to at least help some.

But then suddenly most of them started to open and close daily with the light schedule, and the Duncan started accepting small pieces of mysis and the last week or so it's been absolutely huge. I had the same concerns as you and the guys at my LFS told me to just let them adjust. So I figured maybe they just all had to acclimate and adjust to the new home and water flow??? I'm still learning my way through this journey and I'm sure others on here with WAY more experience can give better answers.

But either way... Good luck with the journey and new tank!

 

[UnnamedReef]

JBStuka glad you're corals came through! My duncan was open wide for the first few weeks so closing up worried me a bit.

That being said, he's more open than ever now. Neon green skeleton and heads, looking very healthy and eats as much as I'll feed him. Wanted to close the loop on this thread for the next person.