How often do you experience unexplained coral deaths? RTN I suppose?

[exnisstech]

As the title asks. My acro tank has been running for a bit over 2 years and I've had my share of RTN but just accept it as its always a single piece while everything else is good. I lost one if my oldest pieces a month or so ago. Doing well, encrusted and branching out then poof I see white at the base and within 24 hours all of the flesh is blown off and I have nothing but a skeleton left. I lost another one last week but it's a piece that has struggled since adding it almost 2 years ago so again I think nothing of it. It encrusted but never really grew much. I look in the tank today and see another older piece on the way out this time from the top down. This one again was a piece in the tank for well over a year that encrusted and grew but very slowly.
This is my first tank with acros. It has been running over 2 years. No recent change to lighting flow or parameters swings. I've been using AFR for over a year and keep alk mid to low 8dkH. I use IO purple on all tanks with 0 TDS rodi. This tank is 65g total and I do 4g water changes weekly. Lighting is two photon 32s getting 400 - 500 par on the top and 200 ish down low.
Recent test results. Ph is low but has been all winter long. I hit 8 - 8.1 when windows are open. I monitor with a Milwaukee but TBH I've never really paid my much attention because I'm not looking for super fast growth. I have 4 tanks running all doing fine except these mystery deaths. I started dosing ammonium bicarb in February to combat low N and P which has been an issues since starting the tank, it has just always ran as an ULNS and i dosed N and P but things have leveled off after starting the ammonium and i don't even have to dose it very often.

I guess I'm just wondering if individual mystery deaths is just a part of the stick game or something to be concerned about? I haven't added any coral in months and only have 4 fish that have all been in the tank over a year.

FTS from last month. All pieces were added as small frags.

 

[pooootiqe]

I haven’t kept acros long enough or well enough to have single acro colony RTNing; surely have experienced the “nuke the whole tank” RTN though, lol.

 

[Reefer Matt]

Imo, it’s what they do over time. I always diversify my sticks by keeping backups in a separate tank. Not that it happens in every case though. I think rtn and stn are symptoms and not an ailment itself. My guess at the cause is from lighting, flow, alkalinity swings, and bacterial infections among other possibilities. It is impossible to tell which is the direct cause when stn/rtn happens unfortunately.

 

[bobnicaragua]

I think you hit the nail on the head with PH. It’s a huge factor. I dose kalk at night, run a refugium, and have an outside airline.

It started to get warm in DFW a few weeks ago, so I closed the windows. The AC really didn’t run much and my room CO2 meter was regularly over 1200 ppm. ( outside is usually 550-600).

Even with all the things I do to keep PH up, my acros suffered. They lost color and I had my Maleficent and PAC-Man STN.

 

[exnisstech]

I think you hit the nail on the head with PH. It’s a huge factor. I dose kalk at night, run a refugium, and have an outside airline.

It started to get warm in DFW a few weeks ago, so I closed the windows. The AC really didn’t run much and my room CO2 meter was regularly over 1200 ppm. ( outside is usually 550-600).

Even with all the things I do to keep PH up, my acros suffered. They lost color and I had my Maleficent and PAC-Man STN.

I don't run a skimmer because my nutrients have always been so low but maybe I should add one and run an outside air line. I already have a skimmer here and a hole going outside so it would be easy to do. I supposed even I let the skimmer overflow it may help raise my pH a bit?

 

[dwest]

Almost all of my acro problems occur in the summer when my pH runs lower.

 

[bobnicaragua]

I don't run a skimmer because my nutrients have always been so low but maybe I should add one and run an outside air line. I already have a skimmer here and a hole going outside so it would be easy to do. I supposed even I let the skimmer overflow it may help raise my pH a bit?

Yes it does help. I would set it up to skim super dry with barely any skimmate at all. It will help with your PH and if anything dies or goes bad, it will help with that as well.

 

[bobnicaragua]

I looked into a home air exchanger. The units themselves are around $1,000-$2,000 but you need HVAC guys to put them in and the labor cost is crazy! I checked with some handymen and they wouldn’t attempt it.

 

[backbayreef]

Don't feel bad - I lost a HUGE colony (basketball size+) of WWC Yellow Tips over night 2 months ago on my 4.5yrs+ SPS tank. The colony was grafting with a few other corals. I woke up one day and part of the colony was dying. I snipped 2-3" from the white flesh to save it. After the next day, the whole colony and all its frags turned white! All other corals were/are fine. In fact, the same species next to it was/is still very healthy & growing! I don't believe that it's light/flow since the colony next to it was fine. I suspect that it's some sorts of bacterial infection. Parameters haven't changed much... Super weird.

 

[exnisstech]

I looked into a home air exchanger. The units themselves are around $1,000-$2,000 but you need HVAC guys to put them in and the labor cost is crazy! I checked with some handymen and they wouldn’t attempt it.

Ya im running window AC units lol. I recently got a quote for a new HVAC unit and they wanted over $13k and an additional $5k for an air exchange system. Windows units its going to continue to be and no air exchanger. If i were younger I may have considered it but not at this stage of the game.

 

[jguerin88]

I don't run a skimmer because my nutrients have always been so low but maybe I should add one and run an outside air line. I already have a skimmer here and a hole going outside so it would be easy to do. I supposed even I let the skimmer overflow it may help raise my pH a bit?

co2 scrubber would be better

 

[A_Blind_Reefer]

For me, it happens super rando. Some pieces of mine are more prone to reoccurrence, while others have never had an issue. I tried to check everything a few years back, when I had about an 18 months long battle with it hopping from one to another wiping out a few, but basically made the rounds through almost every single acro in the tank (not at the same time, just randomly out of the blue a colony would start to stn then stop and weeks/months later another). As everyone else, my stats are fine…ha. I sent pics around, no evidence of pests. Never figured it out. Ran a full course of Cipro as a Hail Mary (I can already hear the screams from behind the keyboards) and didn’t have an issue for well over a year. Then I added some new man made rock to the sump (in a section that had always been empty), had a large Alk spike…..weird story, and had stn return for months and months and months. Weirdly, this time it only affected one acro (sexys orange passion) that I had multiples of. It spread from one to another, to another, and back, but only that one specific acro. Some are still hanging on. It seems to start up, subside, and return. I’m assuming I have some pathogen in the tank that just barely hangs on for dear life and pops up every now and again. Pretty sure that there’s absolutely nothing I can do but let it ride out. Even if that’s not all I can do…..that’s all I am doing.

 

[backbayreef]

co2 scrubber would be better

True but it gets old after awhile. I run a recirc co2 scrubber and can peg pH to 8.4+ but find it a pita to swap out media every 4-6 weeks. I got the media in bulk to save but honestly not worth it in the end. When I'm done with this batch, I'll just let it be -- honestly can't tell the growth difference between 8 and 8.4.

 

[reefpanda]

Do you do water changes?

 

[exnisstech]

co2 scrubber would be better

It would but with multiple tanks running I try to keep things as simple as I can. Now that spring is here I can open up and pH is usually 8 - 8.2 when the house is open.

 

[cilyjr]

I don't run a skimmer because my nutrients have always been so low but maybe I should add one and run an outside air line. I already have a skimmer here and a hole going outside so it would be easy to do. I supposed even I let the skimmer overflow it may help raise my pH a bit?

It doesn't need to be a skimmer, if you don't want one. You could simply use an air pump.

I run a skimmer all the time and at night to combat dropping pH. I have a large air pump that pumps air in from the outside. It runs when the lights go down. It has significantly reduced my diural swing.

 

[exnisstech]

Do you do water changes?

I've been doing 4g a week on 65g total volume.

 

[backbayreef]

I'm not sure where this convo is heading. Are we saying that acro RTN/STN is due to pH swings? In this case, pH (assume calibrated) appeared to be on the low side, and not a lot of variability?

 

[cilyjr]

I have been keeping a pretty much exclusively SPS tank since about 2008-2009.
I have in the past always had those few random deaths. I, like a lot of people at the time sort of attributed it to large alkalinity swings, I have since moved away from that hypothesis and have leaned far more heavily towards lower pH being a bigger contributor.

Large alkalinity in any swings usually are accompanied by a large pH swings. So I think it was natural for people to think towards that.

My pH had always been on the lower side 7.8 to 8.1 ish. I had always run a calcium reactor in tandem with kalkwasser. A couple of years ago I removed the calcium reactor and went with kalkwasser and two-part. That helped bring my pH significantly higher. I now run in the 8.3 to 8.5 range. The other thing I did was add that air pump in the evening to help reduce diurnal swing severity.

Although I have not completely eliminated STN, I have significantly less issues (1 or 2 in the last year) than I had in the past. I even have pieces that start and recover now which had never happened through in years previous.

 

[bobnicaragua]

I have been keeping a pretty much exclusively SPS tank since about 2008-2009.
I have in the past always had those few random deaths. I, like a lot of people at the time sort of attributed it to large alkalinity swings, I have since moved away from that hypothesis and have leaned far more heavily towards lower pH being a bigger contributor.

Large alkalinity in any swings usually are accompanied by a large pH swings. So I think it was natural for people to think towards that.

My pH had always been on the lower side 7.8 to 8.1 ish. I had always run a calcium reactor in tandem with kalkwasser. A couple of years ago I removed the calcium reactor and went with kalkwasser and two-part. That helped bring my pH significantly higher. I now run in the 8.3 to 8.5 range. The other thing I did was add that air pump in the evening to help reduce diurnal swing severity.

Although I have not completely eliminated STN, I have significantly less issues (1 or 2 in the last year) than I had in the past. I even have pieces that start and recover now which had never happened through in years previous.

Do you think an air pump with an outside line would have any impact for me? I already have outside lines to my skimmer, so the air pump would be in addition to the skimmer.

I wonder what a beast like this would do?

https://a.co/d/heNZkEK