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Originally Posted by drw94
I have a dozen or so montiporas, capricornis and digitata, hydnophora, Bali Green Slimmer, and dozen misc acropora sp. Three clams gigas, derasa, and crocea.
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I notice here that you did not mention the patch of
Pachyclavularia spp. (could be the
encrusting gorgonian Briareum as well, which would be worse in close proximity to your
Acropora spp.) or any other octocorals, etc., was this an accidental omission or are there no other specimens in the tank? These alone could be quite an issue for the system, as either genera of soft coral may be issues for
stony corals, especially when in close contact with the stony coral. Toxicity issues with ALL soft corals arise from many reports of unexplained stony coral recessions in closed systems of less than 1000 gallons (4000 L ) with mixed populations of "SPS" specimens and octocorals, especially those systems where there are large specimens or large populations or with situations where close proximity exists. These octocorals produce large number of substances that are released into the water column, including isoprenoids, terpenes in general, phenols, diterpenoids, carotenoids, sterols, prostaglandins... the list is quite long, and these substances are used for the octocoral to gain a competitive advantage over the quickly growing "SPS" corals in the wild, which will be amplified by the closed circuit natures of our home aquaria.
Although toxicity will vary between individual specimens, Eric Borneman has compiled a list of the octocorals ranked in order of the general toxicity of the Octocorals:
Patterms of General Toxicity of Selected Octocorals
REGULARLY HIGHLY TOXIC:
- Sarcophyton spp.
- Lobophytum spp.
- Lemnalia spp.
VARIABLY HIGHLY TOXIC:- Cldiella spp.
- Paralemnalia spp.
- Sinularia spp.
- Heteroxenia spp.
- Nephthea spp.
- Efflatounaria spp.
- Cespitularia spp.
OCCASIONALLY HIGHLY TOXIC: - Xenia spp.
- Briareum spp.
- Dendronephthya spp.
RARELY HIGHLY TOXIC- Anthelia spp.
- Capnella spp.
This is not to say that just because a specimen is listed on the bottom of the list that it will not be problematic for SPS corals, rather that it has been reported to occur less often that examples listed higher up in the list. That any are listed on the above group of octocorals suggests that there may be issues under the right (or wrong, depending on your POV
) circumstances.
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...last thing I added was a acropora sp and montipora sp about a week ago both frags. My temp at the end of the photo period is around 80 to 81 and at night falls to 78 to 79. all the other corals are doing great.
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Take a good magnifying glass and look at the
Acropora spp. that you last added. Look for what appear to be small golden bugs with a red abdomens.
Acropora can have small parasites related to mites that may or may not give symptoms similar to what you're experiencing in your system. At times, these mites may live as asymptomatic cohabitants where the mite does not appear to have any adverse effects on the coral, but this is usually not the case. More often, the corals are not strong enough or are not receiving enough light energy to have the ability to withstand the parasitic effects of infestations by this arthropod. If you see these mites, don't panic, but isolate the coral in a separate water column (prolly to late now if you see them) and email me, I will send you more detailed info on what you're looking for and some potential treatments (long post).
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The pieces that appear to be bleaching are three different sp. of acropora. I have two frags of one the bleaching acros and the second one looks great and it is higher in the tank. One of the other bleaching corals is a green acro and it is only appears to be bleaching on the areas exposed to light ... just cut the photoperiod by 2 hours. I could raise the lights a few inches but I don't think it will make that much of a difference. All the bleaching corals are in the middle to upper middle of the tank. There are other SPS above and below them.
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This is classic for corals that have not acclimatized to the stronger lighting of MH in a new setting, especially if more than a day or so occurred between their last exposure to strong lighting. Hopefully this is the issue you're experiencing in your system, as it is easily corrected. Go to the hardware store and buy some fiberglass screening material and some 1/4" plastic or acrylic rods (may need to go to an acrylic vendor in your area). You'll need enough screen to cut out some 10 inch squares, at least 3 such squares for each coral specimen that is affected by the bleaching (for all your new specimens). Cut the rods so that you have 2 of them that run the width of your tank for each affected specimen, and arrange them so that they will lay in the tracks of the top aquarium reinforcement edgings. If you're good with acrylic, cut some rectangles that are about 8 " x 2" and glue the rods to the 2" sides on both ends. This will make a large support across the tank that is arranged so the rods are 8" apart and supported on both ends by the edge of the tank. Place these so they are centered over each specimen affected by the bleaching, and place 3 of the squares of the screen on top of each other over the specimen such that they are shaded from the direct light of the bulbs for the aquarium. Do this for each new specimen you locate in the tank. In 3 days, remove one piece of the screen, wait 4 more days and remove the next piece of screen, then in 4 more days, gradually slide the last piece of screen to the edge of the tank such that the specimen in question is gradually revealed to full lighting from the fixture. This will acclimatize the specimen to lighting without causing a bleaching episode. The need to do this will depend on the strength of the bulbs in your canopy (400 watts need longer than 150 watts), the temperature of the water (85F is MANDATORY long acclimitization; preexisting bleaching at 80 F as listed above for 150 watt bulbs, and 250 watt bulbs for newly acquired specimens; prolly only need 5 days total time for newly acquired specimens under 150 watts), and total water quality and potential competition issues (turbid water = less time, bad water = more time, etc.).
I have had
Montipora capricornis frags bleach when moving them from 250 watts Iwasaki 6500 K bulbs mounted at 20" above the water to a display where the same strength bulbs (but now XM 10,000 K) in less than 24 hours and
still had them recover if removed from the insult. It is quite easy for some specimens to have issues even when moved from very similar conditions. Remember that bulb intensity changes at a rate that is approximately a square (multiplicative function) of the distance from the source, not a straight line additive function. Raising the bulb rack a few inches farther from the water can have quite benificial effects if wisdespread bleaching has occurred in your system.
hth, give us more feedback on the situation. If nothing else, move the specimens to the bottom of the tank in some shade for a few days until you can set up the screens. (HEH! I notice the liberal use of epoxy putty in the photos...
)
