250 mh to much
 

ok so i got a 15g standard tank with soft corals. What kind of lighting should i get. Is 250 metal halide to much?

Yes, it's too much. For this size tank, I would recommend you looking into LED lighting. Talk to people in Oceanic Corals. They have a few options.

70 watt or a really high up 150 watt.
LED is good for light, and very low heat, unlike MH but a 250W would be much too hot on that small of a tank.

Standard 15s are 12" deep, I believe... yeah, 150W max. And it will raise the temperature of the water a fair bit... have you considered T5s?

I run a 250MH on my 10gallon nano. If you hang the lights above the tank, it should be fine. Atleast 8" above the tank. But for just softies or LPS 250MH are not needed. Before my 250MH I ran the 50/50 96Watt Corallife light.

I run a 250MH + 2x24w t5ho Giesemann Neptune fixture on a shallow 15g tank (36"x12"x8") with a water line at ~7.5" and the fixture ~6" above the water. My SPS, BTA and candy canes love it. Temperatures can raise a bit during the day, but that's mainly because I have a cover over the tank to prevent my goby from jumping.

-Rich

It is possible to do , as others have stated you might need to consider a methon of heat removal , sm fan for evaporation might work but evaporating nanos is another problem on its own, a chiller would be the best choice.
you could consider a shorter photo period also

light
 

thanks everyone