This might come as a shocker to some, when I point out three cases that indicate the reduced necessity of iodide dosing to grow good xenia and other corals. First, just incase you missed the article by Julian Sprung in a recent FAMA issue (March 1998 pg 38), he discussed iodide and growing xenia. I'll go over part of it here. Julian suggested that iodide dosing is not necessary for growing xenia. At the same time, Julian, many others and I have seen xenia display greater expansion and faster growth when dosing iodide. He did point that out too. He also pointed out the usual, that good lighting was helpful for growing xenia. But his main point is not often discussed. He said that a depressed pH was more of a drawback than anything else for xenia growing. He said that elevated pH would help it grow better. He said that elevated Ph from KW (kalkwasser) use can aid xenia in obtaining proper nutrients from the water. He also pointed out that excessive protein skimming might even eliminate some of these needed nutrients from the water too.

Julian noted that all xenia tend to like high pH and that if the pH is too low, the polyps will not pulse as well and will even develop ragged pinnules on the tentacles. He said that use of KW or C-Balance would boost the pH, improve xenia health, including improved or more coordinated pulsing, and it would improve protein skimming too. (More on protein skimming in a minute.) He pointed out that KW might promote the formation of micelles, tiny packets of organic compounds that clump together in aquarium water, that could be a good source of food for corals like xenia. Xenia can absorb these through the polyps and skin as they catch these organic compounds with their mucus.

Others have noted that iodide additions tend to make xenia produce more slime. Does this promote the capture of more of these food packets? Could this be one of the reasons that iodide helps xenia growth?

At the same time Julian said that Peter Wilkens had been studying the effect that KW has on the formation of micelles (also called "coral food packets"). He believes that the formation of micelles, induced by KW, helps to improve protein skimming efficiency when using KW. Therefore, Julian also recommended that you NOT overdo it with really heavy protein skimming or you could deprive your xenia (and soft corals) of this feeding opportunity. He also suggested another possibility. If you do skim heavily, feed your fish more, so as to leave more of these compounds in your water to feed the corals before skimming can take them all out. Although this whole pH scenario appears to work, Julian noted that it is still his own conjecture and that KW and two part calcium additives like C-Balance may have these effects.

Well, it all sounded pretty reasonable to me, so I took him up on it and added a small uncured cement rock to buffer my 29-gallon aquarium. New cement rock leaches calcium hydroxide and calcium oxide (kalkwasser or KW) as the cement cures. After boosting the pH a little bit this way, I took cuttings from one certain xenia to propagate in this lightly buffered tank now. I used this particular xenia because it was my "problem child" xenia. I have had problems growing and especially propagating just this one type of xenia. Others tend to loose this one type of xenia first if they do loose a xenia. My other types of xenia all grow prolifically and propagate like weeds, with or without my help! The most beautiful xenia I have, the Fiji pom pom, has a slight violet cast to it, and it pulses like a dream! It's almost too simple to grow. But, the one particular problem xenia, a Bali xenia, is really pretty with a white trunk and branches and brown polyp faces. It has problems taking off in my more natural style tanks that receive calcium and buffering only from thick aragonite sand beds. I didn't associate regular pH levels (around 8.2) with a possible problem in growing this one type of xenia since the others flourished so well under these same conditions. So, after adding the small cement rock to buffer the tank's water lightly, I used scissors and a turkey baster to cut a bunch of individual xenia polyps off of the Bali xenia mother colony from another tank. Using the baster, I put these single polyp cuttings in the gravel bowl, in the 29-gallon tank, for the polyps to attach to aragonite gravel inside the bowl. After attachment to the gravel (a few days to a week - xenia is fast), I can easily super glue these new cuttings to other rocks by gluing their attached gravel to the other rocks. Typically my other xenia cuttings, done this way, all work out and attach easily, or most polyps attach and grow on the gravel.

The Bali xenia had been a contrarian. Most polyps cut and placed in a rubble bed or gravel bowl would just wither away instead of attaching to gravel and growing more polyps, like the other xenia do. However, this time they almost all made it! They attached and grew, with new polyps forming quickly. It worked! I made another batch and they worked too!

Then after the cement rock had run out of buffering power (after it was cured) I decided to use baking soda to lightly buffer the tank and try it again. It didn't work this time or on the next attempt either! Maybe there really was something to the use of KW here, rather than just using the simplest buffer? However, I have recommend staying away from KW use for the most part. If you don't know just what you are doing with KW, it is so easy to use too much of it since it most easily precipitates calcium out of your water which results in low calcium levels. Overdosing of KW also binds aragonite sand when the calcium precipitates from your aquarium water and forms calcite crystals in your sand, limiting aragonite sand's dissolving potential. Otherwise, aragonite sand can buffer your aquarium and provide calcium. After all, aragonite sand is what allows me to run reef aquariums so easily, until you mess it up by adding "excess" KW, buffers or two part calcium additives.

I do suspect that it is more than JUST the high pH that did the trick for growing the touchy xenia cuttings when I used the cement rock to boost the pH and lightly buffer the water. Cement also adds other things besides just KW to your water. Cement rock also leaches silicates until it is cured. I need to isolate what it is that did this. I WILL try some light nighttime drip-dosing of regular KW to see if it alone will do the same trick. I will also compare the results of using some other more complete buffers on other batches of xenia cuttings too. By the way, I also had the best results getting this particular xenia to attach and not wither away when I used a finer sand like Reef Sand or GeoMarine grade aragonite sand rather than larger chips and chunks of aragonite. If anyone else also wants to try some testing like this, I would like to compare our test results.

Furthermore, I talked to Dick Perrin and found that he was no longer dosing any iodide in his propagation tanks (vats) at Tropicorium. He said that his cleanest tanks are reserved for SPS and xenia coral growing - combined in the same tanks. He said that the iodide would of course help the xenia a little bit, but at the same time the xenia would put off a substance in the extra slime produced that holds thwarts the growth of SPS corals. He says that omitting the iodide supplementation allowed the SPS corals to grow faster again and the xenia grew just about as well anyway. He does not add ANY trace element additions or ANY additives or supplements! He only uses aragonite sand to provide all calcium and buffering needs. He does use some forced aragonite dissolution besides the natural dissolution of aragonite in very thick sand beds in the vats. He does not use KW or kalkreactors. He says that the elements and trace elements that dissolve from the aragonite sand helps keep calcium, KH (alkalinity), pH, major element, minor element and trace element conditions proper. He says this is plenty to keep everything healthy.

I asked about water changes providing supplementation. He does a 10% water change every six weeks, but just in the SPS xenia vats in which he wants to have the best water quality. He does use the 10% refuse water from the first tanks and does a trickle-down water change to his other tanks. He uses the 10% that he takes out of the first tank and puts it in the second most important tank and then exchanges the refuse water from that tank with the next tank and so on down the line... Public aquariums and zoos do this too. He said that octopus tanks get the first water change and best water quality at public aquariums. He uses Reef Crystals salt mix now. Reef Crystals does have a higher dose of vitamins and various supplemental elements/trace elements than the Instant Ocean salt mix that he used to use. This would still not be considered a major contributor for supplementation though, not even in the SPS/xenia tanks that he puts the 10% water change in first.

Dick Perrin has not only been keeping reef tanks much longer than most of us (since the 1970's), but he has been actively propagating corals since 1973! Most think that reefkeeping is very new and do not realize this. The real popularity of reefkeeping did arrive until the mid 1980's. Dick believes in using the simplest means possible that will effectively grow very healthy reef livestock. In 1973 he started out with 40 watt shop light fixtures and cool white shop lights over aquariums. He says they work, but he likes the better lighting we have today. Sunlight in modified "greenhouses" is now his mainstay, with 400 watt German 10,000 K and Iwasaki 6500 K metal halides providing supplemental backup lighting, one of each bulb in each custom built fixtures.

Growing corals with sunlight at Tropicorium in Romulus Michigan. View of two large coral and live rock propagation vats. (water flow turned off for the picture) The white metal halide lighting fixtures can be pulled out of the way when there is ample sunlight.

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