Well, I got really bored tonight and as some of you know I am building a 25 long clam tank for my wife Originally it had 2 39 watt t-5 HO on it but at 12 inches wide I thought maybe I can squeeze a couple more in. At 12 inches high it will now have 4 39 watt t-5 HO's in it. Didn't have much room to work with but I made all 4 of them fit by squeexzing the refectors slightly to make the added room needed. Just gotta wait until the other 2 bulbs I ordered come in. Hopefully friday. Tis tank should be blinding adn Dastank, You won't have to worry about your clams getting enough light... just make sure they have sunscreen.