150 or 250 watts over a 20" cube?

[vresor]

I'm planning an upgrade of the stock Solana disco ball 150 watt MH fixture over the 20" cube tank and trying to decide whether or not to increase power from 150 watts to 250 watts. The reflector will be a Hamilton Cayman Sun and the ballast most likely an electronic Icecap driving a Phoenix 14K.

I have mostly LPS and softies, but want the flexibility to add other SPS species should the desire grow. Is 150 watts enough for a 20" deep tank, or will I eventually wish I had 250 watts?

 

[Donkeykong]

If you are going to just do a few nice sps frags up high then the 150 will be plenty, you will see a jump in heat from the 250 halide. But if you are going to start wanting to do LE pieces everywhere including down low then the 250 might be a better choice. I guess it comes down to you deciding on what you really want to do in the tank and then picking the best option for that plan.