I'm not sure you can buy based on wattage. I would look at the par map on the item and buy based on your needs. A blanket recommendation of wattage means nothing. What are you goals for the tank? SPS, LPS, softies? This plays a big role on your needs. I see many people recommending noopsyche, but honestly I think any black box leds would work. The more money typically just adds features like programming, number of data points, channels, etc.So three of the 150 watts or the 100 watts? Could I get away with two of the 150 watt version? Thank you!