My Thoughts on Keeping SPS.
So……… You want try your hand at keeping corals commonly referred to as sps. Who can blame you; after all, those sticks are challenging, fast growing, colourful and always in demand.....
In my experience, the logical progression for a reefer is generally along the lines of: glass box filled with fish, then some hardy soft corals, then some more soft corals, followed by hardy corals with calcium carbonate skeletons (generally referred to as lps), eventually followed by the feeling that you have built up enough experience and confidence to try your hand at the challenge of successfully keeping sps corals. You’ll start off with a small cutting (referred to as a frag) from another reefer, hopefully applying what you have learnt thus far and achieve success in watching it grow and attach itself to your rockwork ,encrust and spread out new “branches.” Fortunately, or should I rather say unfortunately, it does not stop here.……… You have achieved success with sps!
BUT…… as with most things in life, it simply is not enough…….. You see pictures of tanks saturated with them, in almost all colours of the rainbow, and even multiple fluorescing colours in single specimens…… As I said, not enough to have one growing successfully, you simply have to have more, you also want those colours, you also want to show off on the internet forums, you also want to be able to trade them with fellow reefers and you also want to have them “infest” your tank…. So you buy a few more, they lose colour, regain colour, grow well and you add some more, make changes to your system to accommodate them, add some more, perhaps even invest in setting up a frag tank and before you know it, you are regularly supplying fellow reefers with frags…….
If you have been fortunate to get to this point, without losing too many specimens, then perhaps this article is not for you…… If you have however lost some during the course of your venture, or gotten to a point where they were doing well and suddenly start dying, then I urge you to sift through my ramblings on how to keep sps corals successfully…………
There is a plethora of information on the keeping of sps corals available to the hobbyists, whether it is in magazines, internet articles, message boards or books, it is out there and sifting through it all can be rather intimidating and confusing in the least…… Writing a single article to try and summarize sps husbandry is near impossible, but what I will try and do here is cover the basics and discuss my opinion on the aspects which I have found to be of paramount importance, i.e. water and water parameters, filtration, flow, lighting, allelopathy, quarantine, acclimatization and tank and stand construction.
I shall make a concerted effort to not digress, but I have to warn you that I will fail miserably……. Partly due to me enjoying the digression and partly due to all the above being related to the point where it’s all completely intertwined and interdependent. I’ll also try and keep the science out of it, or at least reserve it for some future ramblings… After all, I suppose most of us just want to know the how, and only a little bit about the why….. Perhaps this should become a series of articles…….. Or rather…………….. hmmmm…….ramblings………
1.)Tank and stand construction.
I am inclined to discuss this subject last, as I am a firm believer that the success of a sps dominated aquarium largely depends on designing your aquarium around the needs of its intended occupants. Unfortunately, this is not the natural progression for most hobbyists and often, problems encountered later on, can be traced back to an incorrectly designed setup….. We will re-visit this subject once we have covered the rest…..
Again, there is a wealth of information on the net and in hobbyist literature on the water we use, heated debates on Natural Sea Water (NSW) vs. Artificial Salt Water (ASW), a myriad of salt mixes to choose from, tonnes of marketing “propaganda” on what makes one salt superior to another, various methods to purify the water we use for making up ASW or purifying of NSW, I can carry on and on and on……… and on…… Suffice to say that I am not for or against either, have used both successfully and had failures using both… As I will explain, the jury will forever be out on the best choice.
Let us rather focus on what is really important for sps corals in terms of water and how to go about providing it. Having lived in the tropics, dived amongst some of the most remote and stunningly healthy & colourful coral reefs, the one thing that stuck out is the quality of the water………. Which, to me, brings one word to mind: PRISTINE.
Considering the origin of our corals, that should be our first port of call, to provide our inmates with pristine water, or as I will illustrate, as pristine water as we possibly can…….and nothing less.
Our options, as touched on before, are NSW or ASW, so let’s briefly look at what we need to consider when using either, whether it be during the initial start up or whilst performing a water change:
- NSW: At the end of the day, the saying “Nature Knows Best” rings true. If you are able to collect crystal clear, pathogen free, unpolluted water with parameters as found around coral reefs, then yes, nature knows best.
Reality check: IF you can answer yes to all the above, you are probably living on a remote coral islet and your goggles and snorkel will suffice as aquarium viewing tools.
So, we don’t live in the tropics, surrounded by unspoilt tropical reefs, BUT, we coastal folk are surrounded by very similar water. It is however within our power to “address the shortcomings” of our local NSW to a certain degree.
o Considering the proximity of our NSW collection sites to cities, harbors and other “not so clean” neighbours, our primary concern with NSW would be pollution. There are a whole host of potential contaminants to consider most which we cannot test for with our limited hobbyists’ budget. Fortunately for us, the ocean has a massive dilution power playing in our favour, so as long as our collection points are a decent distance away from harbours, sewage pipes, industrial areas, river mouths coming down in flood, etc. and there is a decent tidal exchange, we should be okay. To further reduce the risk, collect your water about an hour before high tide, as the tidal current will still be bringing in clean water and the outgoing tide washing away dirty water has completed its task.
o A minor concern which is closely related to pollutants in NSW would be the addition of those words which make reefers in SPS circles cringe, i.e. nutrients, predominantly Nitrate (NO3) and Phosphate (PO4). Their ability to act as “fertilizer” for unwanted algae is well documented and one can write a dissertation on each of them. Fortunately, the nitrogen cycle (conversion of very toxic Ammonia to toxic Nitrite to less toxic Nitrate and eventually to harmless Nitrogen gas) is extremely well managed in nature, so it is hardly a concern, especially when the aforementioned water collection criteria is adhered to.
Unfortunately the same cannot be said for PO4, as in my personal experience I have found elevated PO4 levels of up to 0.06ppm in local NSW, which is several magnitudes higher than the maximum levels encountered on pristine reefs (0.005ppm or lower). Most hobbyist grade test kits don’t measure accurately at such low levels, which leaves hobbyists with only one real practical option, i.e. treatment. Fortunately, we have quite a few affordable options available, with the most common (and practical in this case, being Granular Ferric Oxide / Hydroxide (GFO or GFH). Its use has some minor drawbacks, but more on that later.
o Our next concern with NSW would be accompanying pathogens. There are a host of potentially harmful organisms in the soup we call seawater and the last thing we want to do is add them to our tank unknowingly. Surely we can assume that a vast number of them will die, simply due to the fact that we run our systems at a different temperature than the water they were collected from and our corals should have an immune system enabling them to cope with the onslaught of pathogens? Possibly, yes, but bear in mind that our delicate corals have likely not dealt with and therefore not evolved an immune response to some pathogens which might survive the different temperature…… Worth the risk…..? You decide. If you are not willing to take the risk, you have various options to eradicate potentially harmful pathogenic hitch hikers. The most common methods would be to leave the water in dark sealed containers for up to six weeks and then either using Ozone or a UV sterilizer to treat it. I am not going to elaborate on either of these methods, except by saying that (if employed correctly) they are both extremely effective at killing anything and everything in the water. A word of caution with Ozone, it is an extremely potent and potentially dangerous substance to all life forms and should be treated with extreme caution.
o The easiest “shortcoming” to correct would be the major parameters which are generally considered important to our intended charges, i.e. Salinity, pH, Temperature, Calcium (Ca), Alkalinity (Alk) & Magnesium (Mg). Fortunately, I have found these parameters to mostly fall within the range of acceptability for NSW, except perhaps for Alk. Hobbyist equipments and test kits for Temperature, Ca, Alk and Mg would suffice, as even though their accuracy is suspect in my opinion, they are generally accurate enough to fall within what is termed “acceptable parameters.” They are more often consistent enough for our intended application, which imho is more important than being precisely accurate. We’ll take a more in depth look at parameters shortly……. Digressed already…….Anyway, as I was saying, use hobbyist test kits to measure the Ca, Alk and Mg and adjust to the commonly recommended numbers. Again, adjustment of each of these parameters (whether in tank or for the purpose of doing a water changes) deserves an article on its own, and things can get really complicated when one tries to understand the relationship between CA, Alk and Mg, but more on that later. At this stage, suffice to say that a good supplement will (or should) list by what magnitude a parameter will increase when a given amount is dosed per litre.
Salinity (in layman’s terms, the quantity of dissolved salts in a liquid), is the parameter which I have never found to need “correction” when using NSW, as it has always been within the acceptable range. However, it is worth checking, as it is one of the most fundamental cornerstone parameters in our hobby. The most convenient and widely accepted method to check this is with a refractometer. More on this later.
The pH of your water is another cornerstone of a successful aquarium and should be measured with either a digital pH probe or a reliable test kit.
o Keeping the above in mind, I would recommend the following process for treating NSW before adding it to our tanks:
§ Collect from an unpolluted area, an hour before high tide.
§ Store in dark, sealed containers for 6 weeks
§ Once this period is over and you are about to use it in your tank, heat it to the required temperature
§ Run it through a UV sterilizer, or apply ozone.
§ Run it through several layers of filter wool, followed by filtration through some good quality activated carbon, followed by filtration through a PO4 removing media.
§ Your next step would be to bring the aforementioned parameters to within the acceptable range,
§ Followed by finally aerating the water by means of an aquarium air pump.
- Should you decide the above is not for you, your other option is using Artificial Sea Water. You can either make up the water yourself, or you can purchase already made up water from some pet stores.
As mentioned, there is a smorgasbord of salt mixes available to the hobbyist, each with their own marketing strategy (hype) fighting for your hard earned cash. There is a host of literature, internet discussions and “studies” detailing the breakdown of elements in different mixes. Often brands have two different types of salt available, one for marine tanks and one for reef tanks. Whether rumours that most of the popular brands come from the same bulk manufacturer and is slightly tweaked in terms of major, minor and trace elements and rebranded at an (sometimes ridiculously) increased price, is true or false, is beyond the scope of this article. What is relevant is that, in my opinion, they are all pretty close to each other in terms of major element composition and most fall within what is deemed as “acceptable” parameters. When we take a closer look at parameters, you will understand that it is hardly justified to pay a few hundred more for a salt with elevated levels of for example calcium, magnesium or the latest hype around potassium. However, I am not saying that you should go out and buy the cheapest salt on the market, as there are some nasty ones out there. Simply choose a reputable brand with parameters which fall within the acceptable range.
o Once you have chosen a brand you are ready to mix up a batch with some freshwater. The most acceptable water to use is water that has been filtered through a reverse osmosis (RO) unit. An RO unit will remove up to 98% of impurities and the “purity” of the water is often expressed by means of Total Dissolved Solids. To further remove impurities, water is filtered through a de-ionising resin, which should give you a TDS of 0.0, practically pure water. RO water can be purchased from most aquarium specialist stores, but a owning your own unit will pay for itself in a very short space of time.
o There are other treatments available to hobbyists, such as liquids added to act as de-chlorinators, but once you have seen what a sediment pre-filter of a RO unit looks like after a few months, I am sure you will agree that simply removing some Chlorine and chloramimine is not enough. In fact, whenever I change my RO unit prefilters (about every 4 months) I cringe to think that I drink untreated tap water……..!
o I promised to try and not digress…………. Once you have measured the required quantity of RO / purified water, and poured it into your mixing container, you are ready to add the salt. Most hobbyists will buy salt in bulk, purely from a cost saving perspective, and when mixing small quantities for water changes, it is important to bear in mind that the “ingredients” in your dry salt are not evenly distributed due to settling of smaller particles during storage and transportation. Rolling and tipping over your salt container few times just prior to use will rectify this.
o Before you add your salt to the RO water (NOT THE OTHER WAY AROUND AND NEVER ADD SALT DIRECTLY TO AN AQUARIUM CONTAINING ANY ANIMALS OR LIVE ROCK!) ensure that the water is brought to the right temperature, which in most cases will require heating. This is important, as elements such as calcium is less soluble at increased temperatures, and will precipitate (fall out of solution) onto the surface of the heater. I recommend heating the RO 2 -3 degrees above the required temp, as once you remove the heater, temperature will drop during salt mixing.
o Measure out the salt according to the manufacturers recommendation, paying attention to what salinity their recommendation will yield. Manufacturers sometimes recommend a lower salinity, as it will make their salt seem more cost effective per Kg. Measure out enough salt to yield a salinity of 35 parts per thousand. Add the salt whilst aerating the water by means of an air stone and mix thoroughly using an aquarium power head. The mix should be aerated for at least six hours; to ensure that proper gas exchange has occurred, which will have a significant impact on pH. I highly recommend checking the salinity an hour or two into mixing, and adjusting it by adding more salt or more RO water.
o Do a final check on parameters such as pH, Salinity, Ca, Alk and Mg and adjust if necessary. Your water is now ready to be added to the system.
Should you choose to buy from a pet store, my advice would be to ensure that they are using a reputable brand of salt and as a minimum, ALWAYS check the salinity of the water you are buying at the store.
Now that I have rambled about the very basics of water, I think it's time to start looking at the numbers banded around, the ones people are forever chasing, whether it be in a salt mix make up or in their tanks....... yes, PARAMETERS.