Too much light???

[uwiik]

Hi All,
I run a commercial coral export facility in Jakarta, Indonesia. I have a confusing problem with my SPS quarantine tank. I run a dedicated SPS system with all the fancy equipment I could buy/ make. I run a DIY gigantic needle wheel skimmer powered by dual reeflo hammerhead pumps converted to meshwheel, big rowaphos fluidizing chamber holding 2 liters of rowaphos, run fluidizing aquapharm black gold activated carbon, bare bottom with centralized sump filled with live rocks illuminated by 1 X 150W 6000K MH combined with chaetomorpha on a big basket. Lots of current in the sump plus weekly maintenance to syphon all detritus from holding tanks and sump.
I do not have problem with water quality, Nitrate is always 0, Po4 0.01, Temp 26 C, Ca 440 - 470, Alk 7-9 dkH, Salinity 1.024-1.026.
Altogether I have 15 tubs each measured at 110cm X 70 cm and I keep the water 15 - 20 cm high. Each tubs is powered with 250W 14.000K hamilton, 250W 10.000K BLV, 400W 10.000K Reeflux, 400W 12.500K Giesemann. metal halide are hanged 30-40 cm above the water surface. Flow are provided with 1 X 3/4' eductor on each tubs.
Right now I always have mixed result with my acros...
Some of it will thrive and keep the colors strong even for months, but most of the acros will turn brown in 7-10 days. The mixed result happen with all species, deep water or shallow water.
I suspected too much light, however acros that I put in the corner of the tank where it receive less light also turns brown, it does not die, just turn brown. I might try to reduce lights to 150W considering the very shallow water (tip of the acros are only 2-3 cm away from the water surface) and add more powerheads for more current then see the result.
Any idea, suggestion???
Please keep in mind that I do not need to grow my acros, just keep it colorful for at least 1 month.

 

[Rogger Castells]

IMO it has nothing to do with the lights, it is water chemistry, most likely your water has other pollutants that you are not testing for, are you using NSW? what are you using for top off? How much flow (gph) are you actually moving in these tubs?

 

[uwiik]

I am using NSW. What other parameter should I test?? I have tested Kalium, Iodine, magnesium all within the normal range, and I run activated carbon to counter any chemical pollutant that might be carried with the NSW. It is so confusing because not all of my acros turn brown, about 20-30% will stay bright and healthy with the rest turning brown. Should I try running Ozone??

 

[uwiik]

I have heard so much positive feedback from using T5 instead of MH. Most reported better coloration or brown SPS getting its color back... Any opinion??

 

[ianiwane]

A lot of wild sps do not adapt well to our aquariums. To me that sounds about right, 1/5 of the wild coral actually holding its color.

 

[uwiik]

Problem is browning also occur to my maricultured SPS, to a lesser degree tho. Is it possible that I might be too low on nutrient?? My water volume for the SPS only system is 3000L but I am running 12 inch diameter 6ft tall double hammerhead meshwheel skimmer that pulling out like a vacuum cleaner sometimes to the point where the skimmate colored real light and scarce.... It is the same skimmer design that I use to handle my 20.000L LPS system with excellent result. How do you know if you are too low on nutrient?? However to my knowledge, too low nutrient will result in pale colored SPS not brown.

 

[uwiik]

Forgot to mention. In the system I also mix some cynarina deshaysiana, acanthastrea, and red wellsophyhllia radiata, off course with different lighting scenario, 6X24W ATI T5 Actinic . They all colored up extremelly well, I can even recover completely bleached wellsophyllia within 3 weeks. So to add more to the confusion I think we can rule out too low nutrient problem?????

 

[uwiik]

Too add more to the confusion, I think that my nutrient level is just right, because I do not see any hair algae, brown algae, or any algae grow on the wall and bottom. My intentionally grown chaetho stay alive but grow really slow....