70 Gallon MH LIghting? need Help

here we go i have a 70 Gallon Half Cylinder Acrylic Aquarium 36x18x30 By Clarity Plus.
i dont have much room in the canpoy for lighting, and i want to place the light in the canpoy for the look of the tank.
right now the set up is a Odyssea 18" Metal Halide Pendant Extendable Series. and fits nice in there, i used it for the guts of it.
it has 150 watt Phoenix bulb and 2 14watt act. from odyssea and it is runing on a Lumatek 250W 120/240V Dimmable / Multi-Wattage Ballast at 150w.

the light is about 1" to 2" from top the acrylic tank so every close. from the canpoy.
right now no probs with heat in the tank it i have 2 desk fans in the back the canpoy so not to much heat,it moves the air around alot. but the acrylic does a little bend right below the bulb but noting big at all. 1/4" bow/flex

i want to keep lps and sps in the tank

sps at the cent bottom
lps on the sides of the tank where less light.


is the 150 good for that tall tank?
or should i put in 250 and just mod the fixture ends. and 250 bulb?

so should i mod or not is what i want to know.

 

You could probably make it with the 150w if you are selective about SPS species and keep them fairly high in the water, but if you want to get into some of harder to keep species, I would upgrade to a 250.