giant clams

I just added a 24" 2 bulb T5 light over my IM20 tank. It's an SPS dominant tank thats been running for a few months. I was previously using two 30 watt Nicrew LEDs. Now that I've set up the T5s, everything seems...not as bright. At least not as bright as the T5s I have running over my other tank...

The Sulawesi Beach Exhibit is cared for by myself, Tim Morrissey, at Omaha's Henry Doorly Zoo and Aquarium. The tank is roughly 20 foot wide and 3 foot deep at the front. The display is about 10,000 gallons and the reserve is as well, making for a total near 20,000 gallons. A wave enters the...