HQI Lighting Burning up corals?

[mistro108]

I have a 180 Gallon aquarium, which has a 60-Gallon sump containing cured live rock, a 6" Protein Skimmer, and a 40-gallon refugium. All of this has been up and running for about two years. The lighting system has three HQI metal halide bulbs and two 96watt compact actinic fluorescents.
Have about 8-9 fish (all healthy and established) and yellow polyps which seem to be doing very well. I have tried adding some corals (torch coral, open brain coral, mushroom corals, sarcophyton leather and yellow leather, trumpet coral and one bubble tip anemone) this was split into two time frames; not added all at once. All of these new additions eventually dies in about 7-14 days. The water tests perfect: salinity 1.020, pH 8.3-4, calcium 435, alkalinity of 350ppm, adding iodide, magnesium, calcium, strontium in modest amounts every week. I'm puzzled why I'm not having sucess with new corals. Suspecting that lighting is too intense?? Can someone help me?

[Allmost]

when I ran MH lighting, I had the same Issue, but then when introducing new corals, I used to place them really low and move them up day by day (as most softies are stored under T5s at most in LFS so a change to MH is too much stress for them.

you could alternativly move the lighting higher and move closer daily, cut the photo period to a couple hours and increase daily, or use eggcrates to diffuse some of the light and move that out eventually.

in general, I never had success with MH and switched to all T5HO

less heat, better coloration, and no accilimation

[Percula9]

Well if your salinity is 1.020 this is to low for corals. This is partially the reason they die. Your alk is also way to high. An alkalinity of 350ppm=19.5dkh or 7meq/l is way to high. You need to lower the alk to 150-175ppm. This should fix your problem. Lighting may be an issue, but some of the water parameters you listed are not correct. Stop dosing without measuring first. Bring the salinity slowly to 1.0264 or 35ppt by topping off with salt water. How are you measuring salinity?

[Merfin70]

HQI bulbs are shielded by some form of tempered glass?

[mistro108]

I will raise salinity slowly...I measure with a refractometer. Will also try diverting light. Also, thanks for information concerning alkalinity; adjustment will be made. Any other, helpful comments are welcome and appreciated.

[Merfin70]

Not recommending diverting per se if this is related to my post, looking to ensure you have a piece of tempered glass in front of the HQI lights as I thought that was necessary with DE bulbs to block UV and prevent livestock burning.

Originally Posted by mistro108

I will raise salinity slowly...I measure with a refractometer. Will also try diverting light. Also, thanks for information concerning alkalinity; adjustment will be made. Any other, helpful comments are welcome and appreciated.

[Allmost]

Originally Posted by mistro108

I will raise salinity slowly...I measure with a refractometer. Will also try diverting light. Also, thanks for information concerning alkalinity; adjustment will be made. Any other, helpful comments are welcome and appreciated.

I totally missed your tank parameters, so ignore my post

I'm sure the Issues is from the water chemistry, not the light.

follow what others said also, high concentration of Iodine and MG could be toxic ! so test before adding or if you cant test it, dont add it, do more water changes instead.

[Percula9]

Iodine is not a necessary additive. It will do fine with normal water changes. If you want to divert the light you can get a fluorescent light panel. I use one myself and it works well.

[soulsigma]

Originally Posted by Allmost

I totally missed your tank parameters, so ignore my post

I'm sure the Issues is from the water chemistry, not the light.

follow what others said also, high concentration of Iodine and MG could be toxic ! so test before adding or if you cant test it, dont add it, do more water changes instead.

+1