Saltcorner
By Bob Goemans
By Bob Goemans
Dear Dr. Goemans,
I have read your work in Freshwater Aquariums and Marine Aquariums (FAMA) and Practical Fishkeeping (PFK) magazines, and especially enjoyed your article about your solar powered aquarium a while back. Back then, I read that you preferred a shallow sandbed of about 2 inches (5 cm) rather than a deep one for the main system, with your plenum system in a smaller tank below the main system.
Since then, I have decided to go with a Berlin system with a sandbed of 2 - 3 inches (5 - 7 cm) using aragonite sand (2 - 3mm). The tank is 4 x 8 foot and 2.5 feet deep. The system included an Aqua Medic skimmer, Kollarin calcium reactor, Aqua Medic nitrate reactor, and a Deltec fluidized reactor filled with ROWAphos. The system is topped with RO/DI water. I also change 10% water per month and run carbon occasionally, and always use a Poly-Filter. There are four pumps providing a 4000 gallon turnover, which comes from the two sumps beneath my 550 gallon show tank. Lighting includes two 400W 20K Radium metal halides and six 250W 6500K metal halide lamps.
The tank has been running with live rocks taken fresh off the sea floor not far from my house. These rocks are covered with red and pink algae and a host of microorganisms. There are some small gobies, shrimps and crabs that came with the rock. I also have a 6 inch giant clam, and there are no other fish. I have also purchased some Eco-system mud, but have not decided to try it yet. The tank has been circulating for a few months with the rocks before any introduction of new corals, and all water parameters appear to be fine.
The soft (Nephthea sp.) and hard coral (Seriatopora hystrix?) seemed to be doing well, growing on the live rocks. And many new organisms, especially bluish and yellowish sponges, have appeared and grown since. Hence, I decided to add more corals.
But as soon as more Nephthea sp. was introduced into the tank along with some hard corals (3 different Acropora species and 3 Pachyseris rugosa), something happened. One of the new Nephthea dissolved overnight on the first day of introduction, and by the next day, all the other healthy Nephthea died as well. Worst, two of the Acropora corals appear to be dying also. The green one has been excreting something into the water column and it now appears to have lost its bright greenish color and turned brownish green.
But other corals remained healthy, especially the Seriatopora species. All the rocks and corals have been taken from the same shallow reef about 10 feet deep. There is now an awful smell in the sumps and I know something terrible has gone wrong. However, the skimmer is still skimming normally with no visible additional bioload.
Why have these soft corals died off when these were supposed to be an easy species to keep? Why have some hard corals died while others appear to be doing fine? Meanwhile, the giant clam appeared not to be affected. Some of the new young Nephthea sp. growing on the live rocks appeared to be suffering and some of the newer sponges have reduced in size during the last 48 hours. I have not change the water yet.
Please assist me in determining the cause. Have the corals been fighting one another? They have been given plenty of space since the tank is rather empty. As all the corals and rocks came from the same reef, therefore there should not be any problem with compatibility. Would a Eco-system mud refugium help?
I desperately need your expert opinion on the matter and your prompt reply is deeply appreciated.
Thanks
Herbert Hiew
Dear Herbert,
Everyone calls me 'Bob.' Let me first say you have excellent equipment! Yet knowing your water quality parameters would also help in resolving some of these problems (ammonia, nitrite, nitrate, pH, etc.). I also wonder where you are located, as being able to gather your own specimens these days is quite rare.
However, the one comment about a brown substance oozing from the stony corals, which is zooxanthellae, is probably happening because of a change in light intensity. When these corals endure a sharp increase in lighting intensity, they discharge some of their zooxanthellae because it's no longer needed to make a good portion of their food supply. If the change in intensity is too severe, it can often kill them. You have very intense lighting and the change from their original location lighting to your tank may be far too severe for them. In the future, start them on the bottom of your tank, and over the coming weeks move them higher. They could also be affected by what's in the paragraph below.
As for the soft coral problem, I've heard of Nephthea doing that when the new specimen experienced a major difference in salinity, and/or light intensity (or another water parameter). Would either be an answer in your case? And, if one would dissolve, it could radically affect water quality as some have toxins that are still not understood and/or what else would/could be affected by these chemicals. And with the sump water smelling (what kind of smell?), it is probably time for a major water change. And sponge reaction is a clear sign of a toxin - but what is a good question. Water change, water change, and water change appears to be the next move.
Cheers,
Bob
Hi Bob
Apology for addressing you as anything other than Bob.
This is my second e-mail to you today. I understand that you have reviewed the new SpectraPure LiterMeter III in the March, FAMA. However, I did not have a copy, as it was sold out at my local bookstore. As I have placed an order for it, including a water exchange module to change my water, I want to know if it's a good idea to change my water slowly using this unit. Would it affect water chemistry?
Also, I have heard about the ECO-Aqualizer but was skeptical until I read your review. I still do not understand the working theory behind the device. But as long as it works, I am willing to give it a try. However, without electricity to power the unit, how long would it last? Is there a resin or bulb to change?
Also, I noticed that the manufacturer has them in three sizes, but none big enough for the tank my size. Could it be installed in series using only one pump?
Please advise.
Herbert Hiew
Third Letter
Hi Mr. Goemans,
Thank you very much for your insight.
First of all, I am living in Brunei Darussalam on the Island of Borneo. I have harvested the specimens about a mile off shore at a depth of 10feet. I only take one or two specimens at a time when I go out to sea. Most of the specimens were taken from the seafloor already detached from the coral formation. Many were broken off either by ship anchors or damaged from heavy current. The temperature on the reef is 28°C.
I went out to the beach directly across the island and took some sample readings after reading your e-mail. pH 8.2, KH 6, SG 1.0215.
The parameters in my tank are: pH 8.1 - 8.3, KH 7 - 8, SG 1.0225, PO4 - 0, Nitrate 2.5 - 5ppm, Calcium 400, Nitrite and Ammonia: 0, Temp: 26 - 27°C
I noticed a difference between the SG between my tank and the sea. Is it considered major? I am also taken back by the KH level in the natural seawater. I have read that it should be kept above KH 7.
Since the last e-mail, I have changed 10 percent of water. The microorganisms seemed to be recovering now. Some sponges did shrink in size after the trouble started, but they have resumed growing since. The rate was surprisingly fast. Is it normal? New small Nephthea brunches growing from the live rocks were affected during the first few days, but they too have recovered.
The greenish hard coral, which was oozing brown substance, have died. However, there was new greenish growth appearing once again from the base and it did not look like algae. What could it be? The same greenish growth could be seen affecting another coral not far from it.
I have a lot of bubbles in the tanks from photosynthesis, mainly from live rocks and the sand. I read that it is good to a certain extend because it meant pH would drop during the night when algae consumed oxygen. Would it actually make an impact on my system? I understand that many hobbyists used Kalkwasser during the night. Since I have a calcium reactor, do I still need Kalkwasser?
I have not added anything since. How long before I could resume adding?
Actually, I have left out something in my earlier e-mail. The original chiller was removed because it was not designed for the tank. Only when my new chiller arrived three days ago did I realized the extend of the problem. The temperature was reading 35°C when the new chiller was installed. Could it be the source of the problem? The highest recorded temperature measured in the sea during dry season was 32°C and the lowest was 24°C during raining season - readings taken from my dive computer.
Would adding the miracle mud help? I understand this has become very popular in America and beginning to be in the U.K.
As I am living in a country without any marine shops, and all of my knowledge has come from elsewhere and constantly read Practical Fishkeeping (PFK) and Freshwater Aquariums & Marine Aquariums (FAMA) to help understand my hobby. I also used Kent Marine salt for water changes with RO/DI water made with SpectraPure equipment. Would it be advisable to use the water from the sea? The water is usually green but clear during the dry season. It does become murky during raining season.
Please advise
Herbert
Dear Herbert,
It sounds like the problem is solved! You say the reef temperature where the specimens were taken was 83°F (28°C) and your aquarium was 93°F (35°C) when the specimens were added. From what I gather from your letter, the wild specimens on the actual reef in your area can handle higher temperatures during the dry season, and that would only be possible because they experience a very gradual change in water parameters. Since your chiller had gone down before the new specimens were added, your aquarium temperature was far above the temperature where the new specimens were coming from. The sudden water temperature change simply destroyed them and the chemicals from the disintegrating new specimens affected some of the established animals in your aquarium, which had mostly adjusted to the gradual temperature rise. Its amazing to say the least how resilient some of these invertebrate are, along with their recuperative powers when experiencing "gradual" changes as you can see by the recovering specimens. As for the new greenish growth, I'm not going to venture a guess, but in time the answer will become clear. Let's hope its new coral growth.
I would recommend another two 10% water changes before putting more animals from the reef in the system. And, I would slowly acclimate these new specimens from the wild in a holding/quarantine tank before placing them in the main system. Be sure temperature and other water parameters are fairly equal with the main system before placing them in that system. A little care here goes a long way in the longevity of these animals and those already in the main system. And since your present level of calcium is right in line with what's in the wild, I would not consider using Kalkwasser at this time.
As for your other questions, the specific gravity difference between your tank and the beach water is not enough to be concerned about. And as for KH appearing somewhat low in the seawater, so is its specific gravity. If the specific gravity were higher, the KH would also be higher, and in fact, so would the calcium level. I would venture a guess there is a goody sum of freshwater entering your surroundings, either from land run-off or seepage from below.
And, alkalinity can be measured three ways: milliequivalents per liter (meq/l), German degrees of hardness (dKH), or parts per million (ppm) of calcium carbonate. The most commonly used and more correct measurement is meq/l. It measures, in molar concentrations, how much acid can be neutralized by a given amount of alkalinity. A less usable expression is one that expresses the German KH (degrees of hardness), which is an oxymoron since it has nothing to do with hardness. KH, sometimes referred to as dKH, is only the calcium carbonate and magnesium carbonate in the system, not the "total amount of buffering agents" in the system. In essence, dKH readings are really more guesswork at what a system really contains as a "totally" usable base to neutralize acid. Anyway, the conversion for the three units is 1 meq/1 = 2.8 dKH = 50 ppm calcium carbonate. What range, either in meq/l or dKH is required for good maintenance of alkalinity is open to much interpretation. In my opinion the dKH maintenance range should be between 10 to 12 in most reef aquariums.
As for the bubbles, it will drive pH higher during the day and as long as there's not a radical downward slope during the night, I would not be overly concerned. I would test pH during the late daytime, and again early in the morning. If your pH stays in the 8.1 to 8.3 ranges, I would not be concerned. However, I do suggest testing magnesium and relating it to the present specific gravity to find out if it's correct. Low levels of magnesium can yield wider swings in pH.
As for the Miracle Mud product, I see no reason to use it on your system, however, if having a refugium full of worms and crustaceans and macroalgae is of interest, then go for it. You already have excellent equipment that is designed to help promote a nutrient poor system. Why add more things to care for, and why connect a nutrient rich system to a system that is supposed to be nutrient poor!
Whether to use the local seawater or not is difficult for me to answer. I'm not sure of how human waste is handled in your area, or that of soaps used to bath and wash clothes. This is a growing problem worldwide with many countries taking the least expensive way to go and dumping it into the oceans. Believe me, it will come back to haunt us sooner or later, and in many cases its sooner than we thought possible. Unless you are very sure about the quality of the seawater, I would continue to use a dry salt mix and RO/DI water.
As for the Product Review of the SpectraPure Liter Meter III, it is my understanding that has yet to appear in FAMA as of this date (May/03). But I'm going to attach it as a separate file so you can read it. And to answer your question, the slow exchange of seawater in your aquarium will certainly reduce the shock associated with any single amount done at one time. Also, the slow exchange rate reduces your maintenance time when its time to vacuum or clean the aquarium. Since the water change will be accomplished automatically in 150 small and equal withdraws of aquarium seawater and additions of new seawater per day over a certain period of time (decided upon by the user - days or weeks), its simply one less chore on cleaning day so to speak. So, you can have any percentage of your aquarium water changed every two weeks for example. All you need to do is have a place for the withdrawn water to flow into and keep the seawater replacement container from getting empty. In fact, I set this replacement system up on a client's tank and it worked perfectly.
There's no doubt the controversy surrounding the ECO-Aqualizer has been turbulent to say the least. While speaking in Chicago early this month at the first IMAC Marine Conference I mentioned the sad state of affairs on some websites where some individuals apparently use controversy and sensationalism to keep their names in front of the public. In my opinion, they have closed minds and continue to think "in" the box! Its time for a change and I hope aquarists see that the picture being presented by some of these folks is counter to the wellbeing of our hobby. We need to support new and different ideas, however, continue to question those that present new concepts, yet do it in a professional manner. I should also mention the device needs no source of electrical power, nor are there any components that will ever need replacing. Simply flow water through it at the recommended rates. And I understand the unit is good for at least 20 years! As for your system, I suggest contacting the owner of the company, Carl Denzer at: carldenzer@sbcglobal.net as he will resolve that issue.
I hope this has been helpful and keep me posted.
Cheers,
Bob
Hi Bob
Thank you very much for your insight. You have opened my mind on many things, which I never considered. Your suggestions have allowed me to analyze where I should be going with my hobby and how I looked at things.
Yes, you were right about the possible contamination to my local seawater. There is no sewage system and so everything goes straight into the sea! Hence, the live rocks closer to land are often covered with a slimy coat of filth and a host of algae (red cottonwool-like and red and black slime algae, etc).
I have installed the LiterMeter III with the water exchange modules and I am truly pleased with it. So far, it has been running perfectly. I am still waiting for the Eco -Aqualizer unit.
I would like to add a Caulerpa refugium to reduce my other efforts for nutrient export. I intend to run a bypass from the overflow into the filter filled with two inches of sand. I understand that the water flowing into the filter should be slow. I plan to have a 200 liter tank. How fast should the flow rate be?
Now, I would like to share my observation of the reefs around my area of interest.
I have been diving the local reefs for the past ten years. I have seen reefs disappearing for good and new reefs appearing. The island where my corals were taken is such a place. Often, its reef is smothered by filth from a nearby river. And soon its corals would be choked to death. But within six months, a new and greater and more prolific reef would replace it. The new reef would be as grand within one and a half years. The old reef is still covered with endless forms of algae (red slime, green, black etc). Its current is strong most of the time, and pollution is quite evident, yet some coral species seem to survive there. Why are these corals still growing in these seemingly polluted waters? Like I said, the KH is only about 6 and SG1.0215. Have these reef inhabitants grown accustomed to the pollution? Hence possibly, better closed-system aquarium subjects?
There is another incident that occurred seven years ago. Brunei Darussalam has never seen a typhoon until that day. Nobody knew what happened until it was too late. When I went to the beautiful reef about ten miles offshore, I was shocked to see total devastation. There was nothing but rubble - nothing! The entire reef had been covered by sand. We divers never returned to the spot because it was so destroyed. Then three years later, somebody went and saw something amazing. I went the following week and saw a totally transformed reef.
It was bigger than before and even more prolific. The reef life was amazing. How could a reef grow back from rubble in less than three years baffled me. Now, seven years later overall, the reef has expanded another 500 meters and is covered with more varieties of corals and fishes. Simply amazing!
I see the world crying foul play and proclaiming that the hobby is destroying the reef. But as a keen observing diver, I have seen reefs come and go endlessly. It's like a cycle. I tend to believe that the sea is greater and more mysterious than people think. Like the forest - a fire is not necessarily a bad thing. Maybe, the sea is ever changing just like the entire planet.
I have since included a sea cucumber into the tank. It has been in there for two weeks now. It consumed sand endlessly moving from one place to another. It did also consume some algae but appears to be staying away from some areas of detritus. Is the sea cucumber getting enough food? I do not have any fish in the tank, just the natural small gobies, shrimps and crabs that came in on the live rocks. Hence, I never feed the inhabitants. I feed the corals with Two Little Fishes Marine Snow and H&S Marine deluxe. I find the two products very similar. Should I vary the food using other products? I cannot obtain live phytoplankton in this country, as nobody would ship it by mail.
Please advise,
Herbert Hiew
Dear Herbert,
Thank you very much for the follow-up letter and the description of the surrounding areas. I've seen similar areas where both animal and human waste are piped to offshore areas and discharged without any treatment. In fact, the last environmental impact study that I accomplished was at an island belonging to a foreign government and it had 100,000 gallons of animal waste on a daily basis going directly into the sea. They 'thought' it was falling into the abyss and disappearing forever! Not true, as this "stuff" was separating into different compounds and stratifying with much of it seeking higher levels in the seawater. It then was pushed by water and wind currents and simply added to the other causes of why coral growth was lacking along a certain portion of the shoreline. About a year later, after a very violent storm rearranged that coastline and destroyed most of the facility discharging the waste, I had the opportunity to revisit the area. I saw new coral growth in the area, which meant that the massive water change to the local area and the halt to the majority of the waste products had a positive impact on the area. Mother Nature is determined to survive, sometimes with or without our help. And as for your area, coral animals are far more resilient then we think! And in the wild, slow environmental changes bring biological changes to the existing animals that encompass those areas. Sometimes it's for the better, sometimes not. However, one thing for sure, life wants to go on no matter what shape it takes or the condition of the existing environment. Yet, if we want the pristine reefs that we see in travel brochures, we have to help Mother Nature in some areas. And, there are people who are dedicating their time and resources to just that and you might be interested in checking out their website at www.atollreef.org as it's a group that I personally plan on helping do just that!
And, its difficult for me to say if there is sufficient pollution in the areas of coral growth encompassing your island to substantially affect them without some serious testing. And if the currents are as strong as you say, I doubt pollution lingers for any length of time. However, in nearby coastal areas, its evident pollution exists with all the existing cyanobacteria growths. It sounds like a beautiful area, yet needing the attention of caring individuals such as yourself. Could be a group of concerned individuals should be formed to evaluate the local environment and bring forth those findings to those that have the power to make needed changes.
As for the Caulerpa refugium, that is a possible way to export some system nutrients. I say some because its known that Caulerpa release a toxin called Caulerpicin that can inhibit coral growth and possibly kill some fishes. However, it and organic leachates from Caulerpa that yellow bulk water can be removed with adequate protein skimming and/or proper use of activated carbon. If you do decide to go the road of a Caulerpa filled refugium, the type of species and the harvesting of it are an important aspect for success with this type system. Racemosa, or what is sometimes called "grapevine" Caulerpa is ideal because it's a fast grower. However, the excess must be thrown away, as herbivores will not eat it. Two slower growing Caulerpa species, mexicana and/or prolifera, are excellent foods for herbivores and the excess can be used as a very healthy food source for herbivorous fishes. As the Caulerpa grows, always harvest the oldest one third every few weeks - of course, that time frame depends upon its growth rate but I think you get the point. As for the flow rate between systems, one turnover of the refugium per hour should suffice. And yes, a shallow bed of about one or two inches of sand will suffice for in refugium.
I should add that from what I'm hearing about the ECO-Aqualizer, protein skimmers work much better after one of these devices is installed. Its my understanding the ECO-Aqualizer breaks up the larger water molecules that contain locked in nutrients and makes their removal from the system via skimming a much more efficient process. So you may want to wait until the ECO-Aqualizer is up and running before you decide on installing the refugium. Could be it won't be necessary, saving yourself a lot of extra work.
As for the cucumber, as long as the body size does not dwindle, I would not be concerned. If it does get smaller, its time to return it to the wild where it can get proper nourishment.
And as for some other foodstuffs for your invertebrates, you probably know that phytoplankton is at the top of the numerical food chain pyramid and is of great importance to many of the invertebrate we strive to maintain in our reef aquariums. You could culture it yourself and the 'how to' is explained on my website.
Again, thanks for your letters, and hope this helps.
Cheers,
Bob
