Help! Setosa suddenly dying??

[CampAquarium]

That's great to hear that you were able to get professional advice and take decisive action to help your setosa.
Following the shop's advice and going through those steps was a top-notch move. That glue barrier trick is a real game changer.

As for the critters you found during the dip, those brittle starfish and that bristleworm are typically harmless roommates. But hey, better safe than sorry, right?

The salinity adjustment was another smart move. Corals can be a bit finicky with salinity, so a slight bump could make a difference. Just remember to keep a close eye on your water parameters in the next few days since you've made some tweaks, I'm sure you know that already.

One thing that caught my eye was the sand bed issue. Sand can sometimes be a sneaky host for bacteria that aren't too friendly to corals. In the future, it might be worth considering giving corals a little elevation, like placing them on rocks or other structures.

A deep sand bed (DSB), roughly 4-6" deep, can form an anoxic zone that sustains anaerobic bacteria. This bacteria helps reduce nitrate in the tank. In contrast, a shallow sand bed, typically less than 3", doesn't support the growth of these beneficial bacteria. Instead, if not regularly cleaned or vacuumed, it can rot, leading to the growth of harmful bacteria and algae. Disturbing a mature DSB can also cause a mass die-off of the beneficial bacteria, leading to a rotting and stinking sand bed.

So, if your setosa was touching the sand, and the sand bed wasn't properly maintained, it could have introduced harmful bacteria to the coral, leading to tissue necrosis. Remember, it takes about a month or more for a healthy bacterial community to establish in a DSB, and during this time, it's best not to disturb it.

The sulfur dioxide byproduct from anaerobic bacteria in deeper sand beds can also be harmful. If you've got a deep sand bed, it's recommended to stir the substrate to degas it once or twice a month to prevent buildup of harmful gases. A remote DSB in a sump is another solution to avoid this danger, as any gases can bubble up to the surface without harm to the livestock.

Keep a keen eye on the sand bed condition and manage it properly based on its depth. This way, you can maintain a healthy environment for your corals, and hopefully prevent future issues.

I've got to say, you're really going the extra mile for your setosa and it shows. I'm rooting for its recovery! Keep us in the loop on how it's doing!

Yeah, it’s smack in the middle of our tank, and is definitely the first thing you notice. It would be super heartbreaking to lose it since it’s really our showpiece. Plus, it’s a living creature that has clearly thrived so far! I can just sit and watch it die!

I don’t think we’re in the clear on this one yet, but I’m tentatively hopeful right now.

Anyway, super interesting notes on the sand bed. Ours is about 2.5 inches deep. We do vacuum it occasionally, but sounds like it may be a good idea to do that more often.

 

[arnavfactoryfishtanks]

I totally understand how you feel about your setosa. These creatures are indeed captivating and it's clear how much you care for it. The way you're fighting for its survival is truly admirable.

It's good to hear that you're finding the information on the sand bed helpful. Given that yours is about 2.5 inches deep, it's in that zone where it's not quite a deep sand bed, but it's more than just a surface layer. Regular vacuuming is indeed a good practice at this depth. Increasing the frequency might be worth considering to help manage the bacterial balance and minimize any potential issues.

Remember, it's not just about the struggle, it's also about the resilience. The very fact that your setosa has thrived so far under your care is a testament to your skills as an aquarist.

Let's stay hopeful and keep doing our best for the setosa. I'm cheering for you and your coral! Please continue to share updates, and don't hesitate if you have more questions or concerns. We're all in this together.

 

[Dburr1014]

Nothing Better Than A Nice Bare Bottom | Reef Builders | The Reef and Saltwater Aquarium Blog

In the aquarium hobby, one of the most significant debates when building your reef tank is to decide a bare bottom or to use a live sand bed. Let's discuss the benefits and disadvantages of both.

reefbuilders.com

 

[CampAquarium]

Updating here in case others have this problem too. Unfortunately we ended up losing the rest of the setosa. The glue barrier line tactic worked for about 80% of its length, but the 20% where the STN continued to progress just could not be stopped. However, a healthy piece of the setosa that broke off much earlier in this saga (basically I accidentally fragged it while trying to treat the STN in the first few days), is doing just fine in a different spot in the tank.

So I guess, if we ever have the misfortune of running into this problem again I would...

1) Frag a piece of the coral much, much earlier, especially if I can get a pretty large one. I can’t help but think that if I had been more aggressive with separating the healthy tissue from the sick tissue early on, that we could have saved maybe 2/3 to 1/2 of the setosa.

2) Still use the glue line around the fragged edges. It worked well enough that it seems like a good thing to keep in my treatment plan as an additional tactic.

 

[FishKeeper.mp3]

Possible monti eating nudibranchs, those things are the reason all my monti colonies are dead, dipping and checking for eggs is the best I can recommend to you.