Well, it was a difficult fall for my little reef. Earlier this summer the tank was cruising. I was getting great growth and felt bold enough to try my hand at SPS with a few easy leproseries and cyphastrea. These grew, a few like weeds, and at Reefapolooza NY, I grabbed a Montipora Digitata to test the waters of branching SPS coral. To my delight, it encrusted, grew, and had good color and polyp extension. My rocks were hardly visible beneath a blanket of coralline algae and the tank was showing signs of maturation. I decided I was ready for a large batch of relatively forgiving SPS coral. I loaded my shopping cart with Seriatopora, Stylophora, Montipora, and a few select Acropora from
Tidal Gardens and Saltwater Aquarium’s ORA shop. I wanted the hardiest possible Acropora so I chose the Acros based off the responses to these threads discussing easy/hardy Acropora. (
https://www.reef2reef.com/threads/w...-of-acropora-are-the-easiest-hardiest.400444/ https://www.reef2reef.com/threads/easiest-acro-is-there-such-a-thing-as-an-easy-acro.935449/ https://www.reef2reef.com/threads/hardiest-acropora-in-the-hobby.404579/) I tallied up the results and chose the top three, see below. Over 30 Acros were suggested as being “easy” however I’ve only included the ones that got multiple responses, unsurprisingly Green Slimer topped the chart.
Shortly after, I noticed some STN working its way up a Stylophora. Within a week, it had spread to 3 Leptoseris, 2 Cyphastrea, 1 Stylophora, and 1 tiny little piece of a Tri Color Valida that broke off the main frag and I glued it to a rock (because why not). From there it spread far and wide effecting all SPS. Notably, encrusting / plating coral were hit first and hit hardest, other SPS were able to hang around for a bit. After it took out all the SPS, It moved to LPS. I was at a loss, I didn’t have perfect chemistry, but it wasn’t awful, and coral that were happy two weeks ago were now necrosing. Even my unwavering Duncan. After receiving an acceptable ICP test I strongly suspected a coral pathogen (and still do). The tank was crumbling in front of my eyes so I bit the bullet and dosed Cipro (100mg/500g, every other night, 5 total doses). The Cipro was highly effective, the STN stopped in its tracks and growth exploded. But It didn’t last, a few weeks later the necrosis was rearing it ugly head again. I had read Mike P’s article here (
https://reefbuilders.com/2023/04/10/managing-tissue-necrosis/) about a similar experience he had with Cipro. He subsequently dosed 500mg/100g to great effect. I followed his dosing recommendations and the necrosing stopped. The only SPS left were small residual encrusted chips left on the rock after I ripped out the main frag. The tank stabilized and growth continued. Most of the remnants have showed substantial growth since then. However, in a devastating turn of events a .5cm montipora frag that had encrusted and grown into a 1 inch frag necrosed a few days ago after adding a few more frags and switching my feeding regime (which I’ll touch on later). Honestly, deep down I always knew the pathogen was still in my tank, waiting for the right moment to rear its ugly head. I must have stressed the small monti which gave the pathogen an opening.
https://www.reef2reef.com/threads/first-rtn-bleaching-experience-what-should-i-do.1004730/
Some folks may be unconvinced it’s a coral pathogen, and I get it, it’s a new tank and I’m a new reefer. But my Goni’s have nearly doubled in size, my torches have added three new heads, and my Durasa clam has been growing at an alarming clip, there is always a centimeter of fresh shell growth on the rim of his bivalves. From my understanding these all require a comparable degree of water quality relative to forgiving SPS such as digi’s, stylophoras, and birdsnests. So why do SPS always die in my tank? And why does it always follow the same pattern?
Goni Growth (and they are deflated these days because the Clowns constantly frolic in them):
Torch Growth:
Fresh new Clam Shell:
My chemistry has been solid, granted it has not been perfect, but I think it has certainly been adequate to keep a digi or two alive. I test alk and po4 twice a week, No3 and Calc every week, and send ICP tests out monthly. My PH peaks at 8.3 during the day and bottoms out at 8.0-8.1 at nights and temp is relatively stable around 79 degrees. Although I don’t think the problem is chemistry related here are some of the chemistry things that could cause it:
- Consistently low nitrate – Problem here is people ran great reeftanks with no Nitrates for years during the deep sand bed age. Nitrates have always been very low since my primary method of nutrient reduction is an ATS. Historically I’ve fed LRS reef frenzy which is mostly fish and shellfish. Fish have a much lower N/P ratio than plants ~(8/1 vs 15/1), so I’m feeding 8 N for every 1 P but my ATS is extracting 15 N for every 1 P. so I’m perpetually N constrained. I was previously dosing neo-nitro to maintain my desired level of Nitrate (you'll see the spike below) but I stopped because I think it may have caused the necrosis somehow. There are a few folks out there that have experienced STN / RTN after dosing N (https://www.reef2reef.com/threads/addition-of-nitrate-and-stn.961462/page-2#post-11968293). Now I’m trying to bring my N back up organically through an adjusted feeding regiment (and maybe dosing Aminos if it gets to that) so I guess well see if things go south again. Also, I view measured Nitrate as a representation of excess N in the system rather than a measure of true usable N. That's because corals prefer ammonia and that's their primary (preferred) source of N, so why does the leftovers (if that makes sense). One thing I just realized, the spike in Nitrate followed shortly after the Cipro treatment so maybe I have some denitrifying bacteria in my tank somewhere (that the Cipro knocked back), my sand bed is about 3 inches deep at the deepest so I'm not sure where it could be.
- Calcium – My calcium has not been great. It’s had some fluctuations, largely because the Hanna test kit is just not that accurate with RODI water so I never really believe the Hana Checker when the results are whacky. I realized last weekend I need to use distilled water and I expect it to be better in the future now that I can actually test it.
- Salinity – I used a BRS refractometer for most of last year and constantly recalibrated it to 35. Per that refractometer my salinity was constantly 35, however, ICP tests consistently showed a salinity of ~33.5. After much diligence on the topic, I switched to a high quality hydrometer in December, which indeed showed my water was at 33.5 ppt (it’s a real thing, refractometers drift over time someone touched on it at Macna this year). Over a few weeks I raised it to 35 using the hydrometer and my latest ICP tests have shown spot on Salinity. Obviously salinity is crucial, that being said, I have seen successful tanks that have a salinity of 33.5, and mine was always stable and not fluctuating.
- Trace elements – Always a question, but ive been sending out ICP tests and dosing individual Captivate Aquaculture trace elements per to get them in line with the below targets.
- Contaminants – I’ve always had high aluminum, this was a result of me using various ceramic media at the beginning, but I’ve slowly been pulling it out and now its down to 40 ug/l. The other big question is Tin. I usually use reeflab’s ICP but I occasionally send out ATI ICP tests. Reeflab does not test for tin but ATI does, I have Tin levels around 24 ug/l… Now I’m fairly certain this comes from a few pieces of tubing in my tank but from what I understand elevated Tin is very common in our tanks (since PVC and tubing leaches it), and usually not a big problem at this level. Maybe the combination of the two is doing it.
Here are my trace elements over the last 8 months, these are all Reeflabs ICP tests with the exception of month 4 and 8, those are ATI ICP hence why there seems to be alot of big swings in those months.
So if its not chemistry, maybe its biology. I sent an acquabiomics tests out before and after the CIPRO treatment (FYI I think they are a terrible company see here:
https://www.reef2reef.com/threads/aquabiomics-a-terrible-company.1025673/#post-12047959 but that’s a story for another day). Its very very cool, but I did not find it very helpful, my vibro was not hyper dominant and I did not have any coral pathogens above the average level. I don’t think that the entire microbiome of a reeftank can be summarized with one Swab. Each coral has its own unique microbiome, and each part of the coral’s body also contains its own unique microbiome. Anyway, below are the before and after snap shots of my tanks microbiome.
Before Cipro: After Cipro:
So long story short, I’m at a loss. I’ve considered getting some TBS live rock to reinvigorate the microbiome, who knows maybe I’m missing a few crucial microbes. I’m going to try and keep my chemistry as stable as humanly possible, and hit the below target levels. I’m also going to try to get my nitrates to 100x phosphates. Maybe the tank will hit some unseen threshold and suddenly be ~mature~. Maybe I’ve overengineered everything and things cannot find equilibrium. It’s frustrating and disappointing. Any Advice would be more than welcome. Anyway I'll upload some pics of the tank for your time below:
Trapeze artist Pom Pom Crab:
One of my favorite microcrustaceans, the Pederson Cleaner Shrimp:
And the herd of Sexy Shrimp who hang out under their gargantuan cousin the Blood Red Fire Shrimp:
