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Galaxy Coral/Health
1/27/08
Hi WWM crew,
<Hi Jason>
I have a quick question regarding my Galaxy Coral. I've had it for
several months and it does not appear to be doing all that well. When I
first got the galaxy, its sweeper tentacles would come out have night.
However, within in the past month or two they no longer appear. Along
with the sweeper tentacle issue, the coral itself seems to be receding.
The galaxy is placed midway up the tank, at least 8 inches away from any
other coral. The power heads are placed in such a way as to give it
indirect current. I feed the corals 2 to 3 times a week – usually a
combination of Cyclop-eeze and various frozen foods mixed with a few
drops of Selcon.
<Good so far.>
My tank details and parameters are as follows:
Tank: 55 gallon + 15 gallon sump.
Weekly 5 gallon water changes using Instant Ocean salt mix.
Dose Kalkwasser in morning using the slurry method.
Water is de-chlorinated tap water (aerated 24hrs or more before adding
salt; mixed and aerated additional 24 to 48 hrs). I will be changing
over to RO/DI this week.
Lighting: 3 X 39W T5 lighting (2 – 10K, 1 - Actinic) with individual
reflectors.
(Icecap 660 ballast supposedly overdrives these to 60W each)
Protein Skimmer: Aqua C Urchin Pro.
3 Power heads for water movement: 1 - Maxi Jet 1200, 1 – *Koralia(1), 1
–
Aqua Clear 30.
Specific Gravity: 1.025 (using refractometer)
Temp: 78 – 81F
All tests are done using Salifert kits unless otherwise noted:
Nitrate: 0
Nitrite: 0 (Instant Ocean)
Ammonia: 0 (Instant Ocean)
Phosphates: 0 (Seachem)
Calcium: 320 ppm
<This needs to be closer to 400ppm.>
Alkalinity: 13 dKH
<A little high, 8-12dkH is a good range.>
pH: 8.1 – 8.3
Tank inhabitants:
1 – Green Coris Wrasse
2 – Percula Clownfish
2 – Pajama Cardinals
1 – Halfblack Angel (have not witnessed it picking on the corals)
- Frogspawn
- Pulsing Xenia (several stalks)
- Candy Cane Coral (4 heads)
- Galaxy Coral
- Various snails/here
I've read through countless responses on your site, yet I still seem to
be at a loss as to what the problem could be. Nothing seems obviously
out of whack and my other corals *appear* to be doing fine (see attached
pictures).
I would appreciate in help or suggestions you can give me <Out of all
the reading you've done, did you consider light intensity? The
Galaxy Coral requires strong lighting to survive. Even if your Icecap
ballast did push the T5's to 60 watts, we are only looking at 3.2 watts
per gallon, not nearly enough light for this species of coral. Read here
and related links above.
http://www.wetwebmedia.com/marlgtganthony.htm In future queries with
images, please resize the images to 200-300kb, much too large for our
use. I'm using high speed DSL and I could not get one of the files to
open after three minutes of waiting.>
Thank you,
<You're welcome. James (Salty Dog)>
Jason
Re: Galaxy
Coral/Health 1/28/08
Hi James,
<Hello Jason>
Thank you for responding to my email.
<You're welcome.>
I am in the process of getting my calcium and alkalinity in check, so
hopefully that won't be an issue.
<Good>
Believe it or not I actually did consider lighting, and most of what
I've read recommended moderate lighting (I verified this in Anthony C's
Book of Coral Propagation). By keeping the galaxy in the mid to upper
half of the tank I had hoped that I would meet that requirement, but it
sounds like that's not the case.
<Yes, three watts per gallon is not considered moderate.>
I thought that the watts per gallon rule was really not a very good
measurement for lighting intensity, is that still the case?
<Yes and no, will depend on tank depth, water clarity, etc. Being an
industrial electrician by trade, let me explain the way I think about
reef lighting. Water clarity will determine the speed at which light
degrades in different aquatic environments. The level of intensity on a
reef with clear water will average about 20,000 lux at a depth of 15
feet, and 10,000 lux at 30 feet.
Knowing where an organism lives in nature will give you a good idea of
the light intensity required to maintain it in your aquarium. Lux meters
are probably the best way to insure you have enough intensity. As you
know, light intensity is measured in watts and a watt is actually
related to a lux. One lux is equal to 1.46 milliwatts (.00146) of energy
at a frequency of 555nm, and is also measured at the source of the
light. However, since the bulbs we use in our lighting systems emit
light of many frequencies, no exact formula can be used when determining
the number of lux produced by a bulb of a specific wattage.
In your case (and I doubt the Ice Cap ballast is actually pushing 60
watts out of the T5 lamps), using the formula as a guideline, 100 watts
of lighting would give you no more than 13,500 lux at the surface of the
water. Again, keep in mind that this is based on a lighting wavelength
of 555nm, very close to actinic lights. In my opinion, 300 watts of
HQI/MH lighting would be needed to maintain this and other stony corals
in your 55 gallon tank. As for the T5's, adding three more would get you
in the ballpark. I feel that the HQI/MH type of lighting is the best way
to go for growing stony corals and clams. As for the Galaxy lighting
requirements, most of the info I read states strong lighting required. I
have a Galaxy Coral in my tank and it is lit by two
175 watt, 14K, MH lamps. The tank depth is 18" and I am considering
adding another 175 watt lamp.>
In response to your comment regarding the size of the four images I sent
-
I'm sorry that you had trouble opening them, but I did resize them
(23KB, 35KB, 27KB and 40KB = 125KB total) so I'm not really sure why you
had trouble opening one of them.
<I'm not either, just once I would like to have an operating system that
can open all photo files.
Thanks again for your help,
<You're welcome. James (Salty Dog)>
Jason |
