Soft corals shriveling and dying- but not leathers???

[max_rosey]

Hello all, and thanks for all the help I've gotten browsing all of your posts here! Sorry in advance for the long post, we've had a strange ongoing issue that I haven't been able to figure out, and I'm hoping some of you can help?

My wife and I have an 11 month old tank (32 gallon fluval flex AIO) with a handful of soft corals, fish, and inverts- and it had been going really well until a month or so ago. All the levels have been consistent with approximately 10-20 nitrates (which i understand should be fine for softies). All the fish, corals, inverts, and live rock are exclusively captive bred/aquacultured. We also have chaeto in the back part of the tank with a grow light that runs overnight after the tank lights turn off.

We've had GSP, anthelia, discosoma mushroom, photosynthetic sponge, and now pulsing xenia all shrivel up and die, but meanwhile the Kenya tree, sinularia, long polyp toadstools, gorgonian, and ricordea florida mushrooms have been doing great with polyps fully extended. All the fish, shrimp, urchin, hermits, and snails are fine also.

It all started when our GSP shriveled up and died, but reading the forums I couldn't find anything conclusive as to the cause. Then the discosoma and anthelia stopped extending and have since died, and now our photosynthetic plating sponge and pulsing xenia are looking rough (see below photos).

A few weeks ago I tried adding polyfilter in case something had gotten in the tank, but it didn't change color at all to indicate an issue. Then I realized that the issue had started when we added a green cabbage leather that had always struggled, but then started very obviously dying- so my hypothesis was that it was relasing chemicals that were affecting some of the non-leathers. I removed the cabbage leather and replaced the carbon, and did water changes every other day for about 2 weeks. At that point I thought the xenia and sponge looked a little better and tried laying off the water changes, but now they're shriveling up again.

Unfortunately we did have one clownfish develop a health issue and pass away (breathing fast and mucous on lower jaw), but we were able to rule out most of the common parasites/water quality because everyone else seems to be fine. We did not add any medications directly to the tank. I'm not sure if that's connected to the softie issue or just an unfortunate coincidence.

The only other factor I can think of is I had started adding live phyto (Reef Nutrition Phyto Feast Live) around the same time the issues started, but then stopped after a month when we started seeing the softies struggling. The only things we add currently to the tank are flakes for the fish, and benereef coral food 2x per week. We do have an issue with some type of pest snail, but they've been in the tank for a few months and hadn't seemed to affect anything previously.

Any ideas as to what could be happening? As a next step, I'm thinking i'll try changing the carbon again and doing some more water changes?

I've included photos of the struggling sponge and xenia below. For the sponge, you can see the lighter areas on the rock where it had been previously before shriveling up.

Thanks in advance and sorry for the long post!

 

[Mar]

Look at phosphate levels. When my sinularia start to droop, my phosphates have bottomed out. They like about 0.05 to 0.07 in my tank but higher doesn’t seem to bother softies that much

 

[max_rosey]

Look at phosphate levels. When my sinularia start to droop, my phosphates have bottomed out. They like about 0.05 to 0.07 in my tank but higher doesn’t seem to bother softies that much

Thanks! Phosphates are at around .25, would that still be too low? Or too high?

We actually hadn't been checking phosphates since we'd read its usually not an issue for softies, but got a phosphate test when this issue started.

 

[Mar]

That may be a bit high especially with your nitrates that much lower. May be a bit out of balance. I have the opposite, lower phosphate and very high nitrate. My softies seem to like it.

You might try a little phosguard, gfo or polyfilter to cut back some phosphate level.

 

[max_rosey]

That may be a bit high especially with your nitrates that much lower. May be a bit out of balance. I have the opposite, lower phosphate and very high nitrate. My softies seem to like it.

You might try a little phosguard, gfo or polyfilter to cut back some phosphate level.

Thanks for the suggestions! I was using an API phosphate test and since .25 was the lowest reading, I assumed that was ok...after more research I see that folks don't have a lot of faith in API for saltwater tanks (all our other tests are Red Sea, btw).

Mar do you (or anyone else) have any experience with Fluval Clearmax filter bags? We just have the basic foam filter blocks that came with our tank, so I'm thinking I can swap one of the pure carbon bags for one of the clearmax ones, either until the phosphate goes down or long term if needed?

We've really tried to avoid the "dramatic swings caused by flipping from one solution to the opposite" effect that seems to happen to many new reefers (i def understand the sentiment though)...so my hope is to find a more slow-acting solution that can be sustainable in the long term and not create a new imbalance in the meantime lol

 

[Mar]

Prob best to get a more accurate phosphate reading than the API. .25 is a pretty large margin of error. Every tank is different and while .25 may not be bad it’s a bit higher than some of the suggested phosphate to nitrate ratios(i.e. redfield ratio somewhere around 16:1 (N : P). That being said you can use water changes or chemical media in limited amounts to target phosphates. The carbon generally picks up contaminants and has porosity to grow denitrifying bacteria.
I had good luck with Poly-filter (www.poly-bio-marine.com) it’s a sheet you can cut to size. My experience has been that it doesn’t dramatically lower levels.

 

[Tcook]

How about a FTS to see what is exactly in there? Do you have any large sarcophytons? Do you run any carbon?

 

[max_rosey]

How about a FTS to see what is exactly in there? Do you have any large sarcophytons? Do you run any carbon?

Thanks for the reply! Sorry, what is an FTS? We have two long-polyp green toadstools, I think those are sarcophytons? Each one is about 2 inches in diameter. And yes, we have the basic fluval carbon packets in the stock filter sponge setup that came with the tank (we've seen lots of complaints about the filters on this tank but so far it had worked for our purposes).

 

[max_rosey]

I had good luck with Poly-filter (www.poly-bio-marine.com) it’s a sheet you can cut to size. My experience has been that it doesn’t dramatically lower levels.

Thanks for the helpful info, I actually already have some polyfilter in there because I'd read it was a way to check for other contaminants also. I've had it in there a few weeks so far. How often to you replace yours?