Too much Metal halide lighting?

[simpp88]

I'm burning my corals. I switched to 175 watt metal halide lights for my 46 gallon bowfront recently. I have new bulbs and per the LFS I started off at 5 hours daily, plus one hour of actinics (4 x 9 watt leds) before and after. I increased one hour weekly and just moved up to 7 hours daily, which was the goal. I seem to be frying my frogspawn, my toadstool and devil's hand will only extend the polyps partially and even an acro is starting to show signs of bleaching.

Solution: I kept the lights at 7 hours of MH and placed two layers of screen below the lights. The tank seems significantly dimmer. I was going to stay as is for at least a week and then try to take one layer of the screen off is the corals tolerate this. The other option would be to alternate each of the MHs on/off a couple of times during the 7-8 hour light cycle.

Any thoughts would be appreciated.

 

[Pseudo69]

My 400W halides on my 120 are only on for 4-5 hours a day with T5 supplementation 3 hours before and 2 hours after and not during the day. Halides put out allot of PAR and can burn soft and LPS corals easily. Also you didn't say how high above your water level do you have your lights?

Shorten your photoperiod and see how your corals react.

 

[stancfii]

+1 what kind of reflector are you using? I'd be running the halide 6 hrs at the most, and move all your lps to the sides and bottom of the tank.

 

[simpp88]

My reflectors are old and pitted, nothing fancy. The bulbs are around 12 inches above the water.
So maybe 5-6 hours a day with some t5s for actinics 1-2 hours would be ideal?
How long do most people keep their metal halides on per day?

 

[simpp88]

And what would be the ideal schedule (eventually, once the corals are acclimated) for SPS?