Leonard Ho - May 11, 1997

Tonight, I will discuss in general the topic of SPS care and upkeep. I had previously planned ondiscussing propagation as well, but will save that for another Sunday because of the shortage oftime. I will forewarn that this speech turned out MUCH longer then anticipated, so feel free to leave anytime if you have other engagments.

I will proceed at a rather fast pace. If I am posting too fast, let Eric know so he can inform me.

As most of you all know, SPS is an acrynomn for Small Polyped Stony (or, as some prefer,Small Polyped Sceleterian; Sceleteria refers to stony or hard corals) . LPS, on the other hand,refers to Large Polyped Stonies such as Elegans (Catalaphyllia jardinei), Bubble corals(Plerogyra and Physogyra sp.), and Hammer/Torch/Frogspawn Corals (Euphyllia sp.).

I'd like to note that SPS are the primary colonizers and fundamental reef builders. They exhibitincredible growth rates (up to 3/4" per year) and it is their skeletons that form the backbone of allreefs. Fused together by layers upon layers of calcerous algae, SPS skeletons form the very liverock that you and I are using in your home aquariam. Tonga and Marshall Island rock, forexample, is composed of predominately dead Acropora CaCO3 skeletons, while Fiji is composed more of massive Porites, Favites, Pavona, etc.

The term SPS is in no way scientific. It is merely a description-based coined terminology. Inessence, SPS refers to all hermaphytic sceleterian corals that have SMALL polyps and corallitestructures (the structure that the polyps form around it). As you can see, the qualificationSMALL is extremely vague. Different hobbyists have varying opinions on what small is. Someconsider anything less then 5 mm (0.2 in) small while others are more liberal, referring toanything less then 10-15 mm (0.4-0.6 in) as small.

Corals such as closed brains (Favites, Platygra, Favia, etc.), Galaxia sp., Hydnophora sp., andsometimes Flowerpots (Goniopora/Alveopora sp.) are those most commonly confused. Somehave even insisted that they fall under an entirely differnt catagory: Medium Polyp Stony.

Tonight, I will use the word SPS conservatively; any sceleterian genus that contain polypssmaller then 5 mm throughout the majority of its species will be called SPS. This includesPorites, Stylophora, Montipora, Seriatopora, Pocillopora, Pavona, and the most notable,Acropora. Until the 90's, SPS had been thought to be impossible to keep in closed environments. Prior to the 90's, I purchased my 1st Acropora and, like many others at that time, watched thecoral slowly waste away. Until 1992, I did not even know that SPS actually had polyps. Believeme, I was completely shocked and happily suprised to see my first sucessful Acropora (which Istill have with me today) produce such beautiful, tiny polyps. Today, SPS corals are kept bythousands of hobbyists throughout the world. The advent of numerous methods, discoveries, and technologies made this possible.

The growing success of keeping SPS parallels the introduction of the "berlin method" and theslow digression from wet/dry external biological filtration. In the oxygen rich (aerobic)conditions of wet/dry's, ammonia and nitrate are quickly converted to nitrate, resulting in anutrient rich buildup of nitrate in one's systems. With the berlin method however, nitrateproduction in and around the aerobic surface area of live rock is in close proximity to thenear-anaerobic conditions found deeper within that same rock. In these anaerobic conditions,nitrate is efficiently reverted back into less harm. Thus it would show that the new methods ofdealing with and lowering nutrient levels and particularly nitrate levels (e.g. Berlin Method and Jaubert's NNR method) have helped yield success in keeping SPS corals. Lower nutrients alsodirectly lessen algae blooms that can quickly choke and overtake SPS corals.

The discovery that SPS corals required significant strontium (Sr) levels in ambient waters alsohelped solve one reason why these corals were once so hard to keep prior. Strontium is a metalcation that shares the same properties (e.g. valence) as calcium. Most stony corals needstrontium to help construct their skeletons. Sr can supplement Ca if calcium levels are too low.Measurements of skeletal contents show that strontium, though not nearly as dominant ascalcium, were found throughout all hermphytic stony corals. It was later discovered thatinadequete Sr led to gradual tissue/skeletal seperation. This may very well have been why somany that attempted SPS corals earlier (like myself) saw a slow recession of tissue.

Recently, some hobbyists have proposed that strontium additions are not necessary. It MUST beunderstood, however, that this does not mean strontium is not needed, but that supplementaladditions may not be required. It is interesting that this new "trend" occured shortly after thepopularity of Jaubert's NNR method AND calcium reactors. Jaubert's method naturallyintroduces a significant value of Strontium into the system by dissolving strontium-rich aragoniteabove the plenum. Calcium reactors, too, introduce strontium in a like manner. I find it safer tocontinue to introduce moderate Sr into the aquariam, especially when neither of the abovemethod/equipment are used. Strontium additions have increased my SPS growth rate.

Technology also played an tremendous role. The sucess of keeping SPS also correlatesindirectly with the improvement in lighting. At the time 5,500K's and 6,500K's MH bulbs wereintroduced, SPS "mysteriously" began to be much easier to keep. Now, there are even more bulbtypes to choose from. I have found that different bulbs and lighting formats yield differentresults. There are numerous factors to consider when choosing what lighting format you wish touse such as initial cost, upkeep, heat, etc., but I will only concentrate on the effects these lightingformats have on SPS in my experience. The new PowerCompacts generate intense lighting veryefficiently, but I have found that these bulbs do not bring out SPS pigments well, nor promotetheir growth as well as Metal Halides. I have not been able to deduce the reason why, but PC'stend to cause lightening of SPS pigmentation and have never produced any significant tip coloron Acroporas. VHO's have yielded better results and corals near the surface of the water near thebulbs have produced great colors and great tip colors, but growth rate is not spectacular withVHO's. Standard output flourescents do not produce neither enough UV nor intensity tosuccessfully keep SPS pigmentation and greatly hinders growth. In my past experiences, SPSunder standard output bulbs almost always turns completely brown.

Metal halides have thus far proven to be the most successful. MH's generate enough intensity tosimulate quick growth. Some MH's emit enough UV-A to maintain pigmentation and tip colorsalone. These include the lower K rating bulbs (6,500K and below). Higher Kelving rated bulbssuch as the German Radium 20000K's and 10000K's, contrary to logic (they are bluer andSHOULD have more UV) don't emit great enough UV-A to always keep SPS pigments. Although some have reported (e.g. pers comm. w/ Steve Tyree and Bob Mankin) being able tomaintain color with these bulbs alone, this is usually not the case. Bulbs with 10000K + ratingsshould be supplemented with VHO actinics to produce both good colors and good growth rate. Lower Kelvin rated bulbs can maintain both growth and pigmentaion in SPS alone, butironically, most still choose to use supplemental actinics because these lower K bulbs are notblue enough aesthetically speaking. It is my opinion never to use bulbs less then 6,500K for SPScorals. 5,500 K have too much yellow and red spectrum, wasting much of the light because SPSdo not use these spectrum for photosynthesis. This "wasted" light, in turn, can spawn algalgrowth (which can use red/yellow/orange spectrum), further complicating the situration. Acombination of 6500K and 10000/20000K would work as well if one desires only to use MH.Through experience, I prefer German 175W 10000K's, Iwaski 150W 6,500K's, Iwaski 400W 6,500K's, and German Radium 20,000K's. I would not use Coralife (any K-rating) nor Venture by choice. As a reminder, it is always recommended to acclimate new SPS to any ofthe above listed lighting formats, no matter where the dealer claims the coral was collected from.

BTW, I have used over 18watts/gallon over aquariams without problems. Acclimation is thekey. Currently, I am using 3 400W (2 Radium 20K and 1 Iwasiki 6.5K) and two 110watt VHOactinic over my personal 120 gallon show, equating to 11.83watts/gallon. Recommend aminumum of 7 watts/gallon for SPS (though there are many other variables such as dimensions,etc.).

Likewise, larger, more efficient protein skimmers, calcium reactors, wave generators and wavemakers have all contributed a large role in keeping SPS corals successfully. Larger proteinskimmers have helped keep nutrient levels (inc. nitrate) low in the aquariam, simulating nutrientpoor waters of the wild. Calcium reactors help maintina Ca AND Sr levels at a consistently highlevel. This is the one major benefit of reactors versus kalkwasser. Ca reactors also maintainhigh alkanity by providing CO2 to produce carbonate (CO3) ions, buffering pH as well.Wavemakers help create the random turbulent water motion that SPS are accustomed to on theforereef. The sudden and random surges (if directed in opposite directions) promotes uniformgrowth and removal of trapped organic mucus around SPS. Without alternating currents, SPS corals will grow skewed in the directon of the dominant current. High water motion haspromoted more rapid growth in my systems.

Other factors that one should be concerned with in SPS care: Temperature, alkanity, pH, specificgravity, and redox levels. I will briefly cover these parmeters.

Temperature: it is now becoming more prevelant to run aquariams at higher temperatures tosimulate the natural environment where temp gets as high as 89 degrees F, averaging 84 degreesyear round. And although I see merits with high temp such as increased growth, I must warn against keeping temps that high if the following qualifications aren't met: You MUST have a lotof water motion, especially at the waters surface. High water temperature creates one majorproblem in closed enviroments: inability for the water to retain dissolved gases. Dissolved gasessuch as CO2 and O2 are particularly important to SPS health. Without proper water motion, gasbecomes poor in the aquariam and causes A LOT of complications in the water (a lot of thewater's composition and chemistry is gas dependent). This is why in calm warm water lagoons,corals, and particularly SPS, do not thrive (Delbeek, 1994). To ensure proper gas exchange, Irecommend either an open canopy or fans behind the canopy drawing fresh air into the canopyfrom the surround room.

Keep water temp consistant. Although in the wild temp can fluctuate up to 10 degrees within anhour, it does not usually occur and does not mean the corals like it. SPS can be extremelysensitive to temp swings, showing polyp retraction with large gradients. Fish, too, are extremely sensitive as temp directly effects many variables in the water such as density. I recommned78-82 degrees F (25.5-27.8 C).

I recommend a slightly elevated alkanity (above 3.5 meq/l or 10+ppm). pH should be kept sameas non SPS tank (7.9 night --> 8.4 day) and I have found no ill effects to this natural pH swing. Some prefer to minimize this gradient. I also recommend a slightly elevated specific gravity (1.025-1.027) then the recommended "rule of thumb" 1.022-1.025. Reason why I recommendhigher S.G (at full seawater strength): minimizes bacterial infections. I believe Craig Bingmanmentioned this (not positive though), but Vibrio bacterial strains and particularly V.vulnificustend to originate and live in lower S.G. water (almost near brackish). This would lead me totheorize (after talking to Steve Tyree) that V.v may not have significant values in reefs and is notimported from the reefs, but rather from collecting stations in the S.Pacific that are located nearriver tributaries, and other freshwater sources where water is both lower in S.G. and contain highnutrient levels where V.v can thrive (unlike nutrient poor reefs).

Redox: I don't consider redox (the value of potential oxidation/reduction reactions) of muchsignifigance and should be monitored, but there is no "right" value. Generally, 270-400millivolts is fine.

Other equipment such as UV sterilizers, ozone generators is purely optional, but if you plan onimporting and exporting large quanities of SPS through your system, I suggest that these twoequipment be used to cut down on viruses, bacteria, and other pathonogens in the water. Because of lack of time, I won't discuss further these two equipments. Questions are welcomedat the end.

For beginners, I suggest you attempt SPS species in the following order: 1. Montipora digitata, 2.Pavona decussata/cactus, 3. Pocillopora damacornis, 4. Seriatopora hystrix, then Acroporaspecies.

Branching forms are best for beginners. Table acroporids and more tightly branching"bottlebrush" morphs require more light and a lot more water current. These should be attemptedlast. Massive formations generally dictate that the coral came from turbulent waters, while finely branched formations indicate calmer water conditions such as found in the backreef.

There is a paradox in the above statement, and if anyone caught it, I'll asnwer it at the end

Without adequete water motion around table and tight, finely branched SPS colonies, tissue willquickly recede where water is stagnant. At times, complete Acropora colonies can suffocateunder its own mucus if no water motion is provided. It is far safer to have more water flow thenless (unlike most LPS corals).

Generally, bright phosphorescent colors such as purple, pink, or blue require A LOT of light andI recommend a significant amount of UV-A emmission. Bright green colors can be an exception. These colors are formed as UV protective pigments by reflecting most of the radiated UV. Blueusually indicates the SPS came from extremely shallaw water since blue is the best UV reflectivepigmentation. This is dangerously general, in most cases, Acropora require the most light,followed by Stylphora, Porites, Montipora, Pocillopora, Pavona, then Seriatopora. This is NOTalways the case though and caution must be taken to give each individual what it needsdepending on how it reacts at different locations within your tank.

Different species also exhibit different natural growth patterns that are not effected by exteriorparameters (water motion, light, etc.) For example Seriatopora sp.do not encrust, whileStylophora, Pocillopora, and Pavona encrust slightly, further while Acropora, Porites, andMontipora genus contain species that are nearly completely encrusting.

Feeding SPS is not necessary. They will obtain 98%+ of their nutrition with light alone. Thisshows how important light is to SPS, so this area must receive careful attention.

There are some organisms that eat SPS corals, so careful attention is required after you purchaseand place a new SPS. Some Mithrax crabs (hairy brown crabs) can eat SPS polyps. I have hadone devour an entire row of polyps on a Acropora. On the other hand, some SPS do come withlittle Xanthiid crabs found within their branches, and these crabs cause no problem at all,defending the host SPS against predators. Some fish also will eat SPS. All non-reef safe fishesshould not be kept. Angels may begin to pick at individual polyps. There are carnivorousblennies (easily mistaken with their herbivorial cousins) that will proceed to eat SPS at alarmingrates. Again, I've had a blenny eat up a Pocillopora as if eating corn on a cob. Circular mouthmarks was the complete give-away to who the culprit was. Tangs will ingest SPS mucus (rich inamino acids) but will not harm the coral itself. Any and all parrotfish is notorious for eating allSPS in one day. Some butterflies will not harm SPS but like angels, can turn its flavorpreferences and begin to consume your prized SPS specimen. Best advice: just observe, andeven better yet, play it safe and not introduce any of these fish.

One last note: SPS can be kept in mixed company with LPS and soft corals, but it is generallyrecommened for beginners to keep SPS alone if SPS is what they want to try. SPS corals aresusceptable to terpenoid toxins that soft corals emit as a territorial weapon, and NEVER win when in contact with LPS. However, once you have experience under your belt, you may wantto try a mixed environment - a truly rewarding and natural environment.

There is much more for me to write, but time does not permit. Perhaps I will be given a secondopportunity in the future to further discuss SPS care (the fundamentals are covered here), andparticularly propagation. I'm sorry if I disappointed any of you who expected a speech about propagation. I just thought it more practical to start with the fundamentals.

For info on Rapid Tissue Necrosis (RTN) that effect SPS, refer to the log of Craig Bingman'searlier speech in #reefs. This concludes my discussion.

Q: What is the typical percent of Sr in Halimeda skeletons, and how does it compare to thepercent of Sr in coral skeletons.

Q: when/if feeding the SPS, what do you recommend?

Q: How much strontium do you add and how do you monitor whether the quantitiy added issufficient?

<Leonard> Sr content within Halimeda (which when dead produce "coral sand") is comparableto Sr content in Acroporas though SPS are more enviromentally sensitive Halimeda will uptakeCa most of the time without much Sr intake

Q: What benefits/dangers are there to the commensal crabs found in sps corals?

<Leonard> I do not feed SPS corals directly. I know of a few hobbyist who try and claim bettergrowth rates, but can not comment personally

<Leonard> Strontium should be maintained at 8-11 mg/L. To monitor, you will have to buy atest kit.

Q: Are you using plenums in your SPS tanks?

<Leonard> With Ca reactors, Sr levels become far more stable and thus you can test lessfrequently

<Leonard> There are really no proven dangers to the commensal crabs found associated withSPS

Q: What Sr test kit do you recommend?

<Leonard> benefits: they defend territory, eat algae forming on dead portions of the SPSskeleton

<Leonard> Sr kits are availible through Hach, LaMotte, and Seachem. Seachem is the cheapestway to go and it does work.

Q: How important is iodine to sps corals?

<Leonard> I have used plenums with my SPS tanks, not currently though

<Leonard> Iodine is important to any sea dwelling invert with tissue (that's about everyone).Though not as important to SPS as soft corals and actinodiscus, levels should be maintained nearseawater levels

Q: Is that a statement from experience, or do you have refs?

<Leonard> 60 ppb (not ppm)

<Leonard> That statement was collected through pers. comm with various hobbyists such asTyree and Sanjay.

Q: len, how do you differentiate aragonite with regular sand?

<Leonard> regular sand? Could you be more specific, because I really have no clue what regularsand is

Q: maybe live sand or just plain crushed coral

<Leonard> iodine may benefit in maintaining SPS pigmentation, no conclusive study though,just claims

<Leonard> actino, I really don't know how to answer that question, but I'll try

Q: Leonard, what method do you use for maintaining your iodine levels?

<Leonard> I use Lugol's, DBW

<Leonard> live sand has a similiar composite (depending on where you get it) to aragonitecrushed coral is calcium carbonate based

Q: In therory wouldn't a Calcium/CO2 reactor supply all the needed iodine to the system???

<Leonard> I have not been able to detect significant enough of levels to support that statement

Q: Leonard, you said 6500k emits more uv-a than 10000k does. Is it form your experience or didyou use uv meter?

<Leonard> Iodine also gets extracted EXTREMELY fast from the water

<Leonard> Acronick, it is from literature and experience

Q: Wouldn't it be bound in the argonite ???

<Leonard> 20000K only emit 57 (funky symbol) UV-A 6,500K emit over 5000

Q: Leonard, what strontium additive do you use?

Q: Well, wouldn't the iodine be in the tissue of the coral, not the skeleton?

<Leonard> Right now, I'm using (moderately) Kent Marine and Salifert

<Leonard> yup, DBW

Q: Leonard, So you suggest I would use the 10,000k over the 6,500k in my 50 gallon reef, forSPS?

<Leonard> Nilsen and Stuber and Wilken confirm iodine helps prevent bleaching in all corals,including SPS

Q: Len, would the amount of aragonite added to a tank have an effect on the inhabitants? is itthe more the better?

<Leonard> When the batch is through, I am changing purely to Salifert

<Leonard> Actino, it would

<Leonard> Without plenum, I use 2 inch worth of substrate bed (livesand and aragonite). Grainsize should be fine, but not sugar sized (1-2mm)

Q: Leonard, Besides Iodine and Strontium, Do you add any other eliments???

<Leonard> John, no

Q: Leonard, I have heard or read from somewhere that the blue pigmentation in Acroporas staybetter under 10000k or 20000k bulb. Is it true?

<Leonard> my Ca reactor takes care of the rest. No buffers needed

Q: Len, can you also stick in a few stuff about Ca reactors? I'm also thinking about them too,thanks

<Leonard> Sugar sized is fine, needs to be a shallow bed, and dissolves quicker, and compactsquicker. More upkeep, in other words

Q: Leonard, I use a Ca reactor too, if there is SR in the Aragonite, why add additional SR ???

<Leonard> Sr content of aragonite varies with the batch, varies over time

<Leonard> a consistent addition can not harm your tank, and provides more stability

Q: That depends on how much you add and how fast it's consumed, right?

<Leonard> cap, yes like everything else :)