At my wits end...

[TDEcoral]

Having phosphate at those levels with zero nitrate could cause problems in my experience.

 

[Biokabe]

Maybe... I did do a Par test and the areas where I was keeping corals are from about 180 -400. The corners of the tank a dark. I will post a picture of my readings. Even if the PAR reading are okay, doesn't mean they are getting the correct type of light.

You think too little light would melt corals? My zoas are not reaching for light - in fact, the palys almost look like they are getting too much. I will add photos.

Thanks for the thoughts!

I think that's enough to tentatively rule out the lighting. 180-400 should be fine for most everything, though a little on the high end for lower-light corals (like palys, as you mentioned). I have had corals melt away from lack of light, but honestly I wouldn't expect the decline to happen as fast as what you're mentioning. Usually when that happens it's more of a slow withering rather than a swift decline.

One thing that strikes me as odd is that your nitrates and phosphates are at ULN levels, yet you don't mention any algae growth in the tank. Without something to 'soak up' those nitrates, even your 10-15% weekly water changes shouldn't be taking you down to 0 nitrates, which means that you have something consuming your nitrates. Ideally you'd want that to be your corals and your clean-up crew, but obviously that's not happening - so where are they going?

The obvious answer would also be one of the first responses here - namely, that you have a bacterial species that is outcompeting everything else in the tank. Unfortunately, I don't know how you would confirm that without manually removing all your rock and starting over with fresh (but not dead!) rock. Given the work and expense involved in that route, I know I wouldn't want to do that unless I knew it was going to fix my problem.

 

[Softhammer]

Are you running carbon? May have missed it, but those softies can be violent towards others. I’d toss a bag of carbon in before splitting atoms.

 

[Scdell]

My tank has hit a wall and I have been trying everything (probably making things worse). I have tried patience. I have tried additives, phyto, dipping rocks, huge water changes, switching salt, different lighting settings, etc., etc.

I have a 150 tall that has been running in some form or another for almost 20 years now. Fish are great. Inverts are great. Anemones great. Corals, not so much.

Right now I am down to mushrooms, some zoas, palys and oddly enough, a gonipora colony. The Zoas look okay but they are not spreading. Mushrooms are spreading some. My paly colony is even dying off - they are shrunken and kind of brown (how about that!). Any new coral I introduce looks okay for a day or two and then starts melting away (my red sea 200 at work is my nurse tank for the poor coral).

In the past, same setup, my tank was jam packed with everything from montipora the reached the full depth of the tank, huge torches and frogspawn, stylopora the size of a half a soccer ball, etc. I kept to fairly easy corals. I don't kid myself about being able to grow forests of SPS but even "beginner" corals don't make it.

I have been experimenting with introducing different types to see if maybe there is a pest that is killing them off. The only one that has made it past a few weeks is a green nephthea and that does seem particularly happy.

My LFS has even thrown up their hands. We sent out to ICP for analysis (I was hoping it was a heavy metal leach or something I could fix) but it showed nothing that would melt corals (mag was a little low - see attached).

We have playing with my Gen 2 Radions but to no avail. Has anyone else had an issue like this before?
Do I just give up and get a big emperor angel and other fish I was never able to have?
Do I tear down and start over with dead rock?

Any suggestions anyone has would be more than welcome!

Equipment:
Reef octopus Classic 150-EXT
2 MP40s
Vectra return
2 gen-2 Radions
Clearwater Algae Scrubber CW-100
Dose Red Sea Alk & Ca with Vertex Libra
Tunze auto topoff
5-stage RODI unit (water in measuring 0.0 - verified at LFS)
Right now using Red Sea Pro salt

Temp is from 76-78
Keep Salinity at 1.024-5
Test screen grab from ICP attached for other measurements

Fish are: 2 Clowns, Leopard Wrasse, Melanurus Wrasse, Sailfin and Mimic Tangs, Firefish, couple of Bangai Cardinalfish, Watanabe Angel (female), cleaner shrimp, porcelain crab, longspine urchin and a emerald crab (think that is all).

You about confused yet? Sooooo many cures!

 

[AquaBiomics]

The obvious answer would also be one of the first responses here - namely, that you have a bacterial species that is outcompeting everything else in the tank. Unfortunately, I don't know how you would confirm that

Well, testing the microbial community is certainly available and may be useful here, but I always like to explore the cheaper and faster options first.

I will say, that from my perspective all the chemistry described here seems within normal ranges. I'd low alk to 7 (like coral reefs in nature), and I'd feed more or reduce nutrient export to raise nitrates. But to be honest I don't think the current alk or nitrate levels would kill corals quickly.

 

[Daddio]

Are you running carbon? May have missed it, but those softies can be violent towards others. I’d toss a bag of carbon in before splitting atoms.

I do have a bag of carbon in the sump...

 

[Daddio]

I think that's enough to tentatively rule out the lighting. 180-400 should be fine for most everything, though a little on the high end for lower-light corals (like palys, as you mentioned). I have had corals melt away from lack of light, but honestly I wouldn't expect the decline to happen as fast as what you're mentioning. Usually when that happens it's more of a slow withering rather than a swift decline.

One thing that strikes me as odd is that your nitrates and phosphates are at ULN levels, yet you don't mention any algae growth in the tank. Without something to 'soak up' those nitrates, even your 10-15% weekly water changes shouldn't be taking you down to 0 nitrates, which means that you have something consuming your nitrates. Ideally you'd want that to be your corals and your clean-up crew, but obviously that's not happening - so where are they going?

The obvious answer would also be one of the first responses here - namely, that you have a bacterial species that is outcompeting everything else in the tank. Unfortunately, I don't know how you would confirm that without manually removing all your rock and starting over with fresh (but not dead!) rock. Given the work and expense involved in that route, I know I wouldn't want to do that unless I knew it was going to fix my problem.

I do have some big bubble algae balls but I also run a algae scrubber. I have not had any major algae outbreaks at all.

 

[Daddio]

What are you using to test your phosphates? When in doubt, let it run a little higher and see what happens.

Using a hanna ULR test kit

 

[Spieg]

I also run a algae scrubber.

This can potentially strip your system of nutrients. Maybe try cutting back on the amount of time you run this each day. You may end up having to dose Nitrate to get your levels to stay up.

 

[Daddio]

need pics of tank for unspoken details conveyed

Excuse the bad photos...

 

[Timfish]

Here's my two cents. Theory is the microbial balance in the coral holobionts and in the water have shifted to an equilibrium unfavorable to corals and it needs to be reset. First, I'd siphon out as much of the old sand as possoble and replace it with new live sand but I would not move any of the aquascaping, sand seems to lose buffering capacity over time and my guess is the microbial processes also shift. I would remove the ATS, algae can dump DOC into the water that promotes pathogens that reside in the coral holobiont. I would run GAC aggressively to remove yellowing and allopathic combounds in the water. I would run a diatom filter for a day or so, this is going to pull out a lot of the microbial stuff in the water and hopefully facilitate corals ability to promote beneficial microbial processes.. Then I'd not do anything else except 10% weekly water changes for awhile.

 

[Daddio]

Thanks everyone! There is a whole lot to think about here. I just need to figure out a good plan to proceed... Some things seem fairly easy and would not necessarily jeopardize the health of my fish. I just need to remember patience and give changes 3 or 4 weeks to manifest... that is the hardest part.

 

[Yevoc]

This can potentially strip your system of nutrients. Maybe try cutting back on the amount of time you run this each day. You may end up having to dose Nitrate to get your levels to stay up.

I am on board with this train of thought. Your existing corals are not particularly demanding. Most of the mature tanks on here are able to maintain measurable Nitrate without issues. You N/P are closer an SPS tank. Think you are too successful

Also prefer dialing back the scrubber versus the skimmer as aids in gas exchange.

 

[Biokabe]

Well, testing the microbial community is certainly available and may be useful here, but I always like to explore the cheaper and faster options first.

I will say, that from my perspective all the chemistry described here seems within normal ranges. I'd low alk to 7 (like coral reefs in nature), and I'd feed more or reduce nutrient export to raise nitrates. But to be honest I don't think the current alk or nitrate levels would kill corals quickly.

Huh, didn't even realize that was a thing that people were doing these days. Might have to take advantage of it myself at some point. =)

Getting back to the OP - I think you're on the money with dialing back the scrubber. In my opinion, always start with the least-drastic changes possible, and dialing back the scrubber fits the bill. What's been going on with your tank reminds me a lot of how my corals were behaving in the midst of a bryopsis outbreak. Difference being, in my tank the algae was in the display - in yours, it's in the scrubber.

 

[ZoWhat]

Some ppl will roll their eyes... or flat-out disagree

....but I have been daily dosing tetraselmis phytoplankton I brew myself from an online seller (Mercer of montana) (I have no hidden agenda in promoting them).

I'm up to dosing 64ozs fir a total water volume of 240g DAILY. I dose at night with my sump return pump turned off to allow the tetraselmis to float around the water column.

Biologically my water quality is amazing. Seeing corals really look fleshy.

My goal every night is to have a slight green tint to my water. By the next day is crystal clear. Not sure if copepods are gobbling it up, or corals or both....but I'm seeing a very stable ecosystem.

The amt of tetraselmis is outcompeting all other algaes allowing the cirals and LR to look fantastic. Corals appreciate the natural food source

WARNING I would not recommend dumping 64ozs syarting Day-1. Too much natural nutrients that will shock the system. But start with 4ozs, then work up to a higher number every couple of weeks.

SIDENOTE: you will have to clean your glass every other day as tetraselmis builds up on the glass. It will NOT spike nuisance algae as it outcompetes that stuff.

Smthg to think about.....

 

[Daddio]

Some ppl will roll their eyes... or flat-out disagree

....but I have been daily dosing tetraselmis phytoplankton I brew myself from an online seller (Mercer of montana) (I have no hidden agenda in promoting them).

I'm up to dosing 64ozs fir a total water volume of 240g DAILY. I dose at night with my sump return pump turned off to allow the tetraselmis to float around the water column.

Biologically my water quality is amazing. Seeing corals really look fleshy.

My goal every night is to have a slight green tint to my water. By the next day is crystal clear. Not sure if copepods are gobbling it up, or corals or both....but I'm seeing a very stable ecosystem.

The amt of tetraselmis is outcompeting all other algaes allowing the cirals and LR to look fantastic. Corals appreciate the natural food source

WARNING I would not recommend dumping 64ozs syarting Day-1. Too much natural nutrients that will shock the system. But start with 4ozs, then work up to a higher number every couple of weeks.

SIDENOTE: you will have to clean your glass every other day as tetraselmis builds up on the glass. It will NOT spike nuisance algae as it outcompetes that stuff.

Smthg to think about.....

Thanks everyone! I had started adding phytoplankton a couple of weeks ago and have been slowly upping the amount. I may have to invest in a kit to grow them if this helps - this could get pretty expensive! Also, I have cut the amount of time the algae scrubber is running by half. Have replaced and doubled the amount of carbon. Will give these things a few weeks to see if I see improvement.