i owuld pull the glass tops on th etank, personally. i feel that although an open top tank loses mroe water to evaporation, you also gain the increased gas exchange, and oxygenation of the water. we were worried as well about hanging th elight from the ceiling. we went through about 8different ideas until we found that there were two layers of sheetrock in the ceiling. we used eye bolts form home depot, and 1/2 inch alligator anchors, and drilled through the drywall, fed the bolt and anchor through, then looped the hanging wire through the eyebolt. the first time we hung it, the light pulled out of the ciling and thank god one of the guys was under it to catch it or it would been 800 bucks down the drain, but the only reason it fell was because the allligator hadnt gone far enough through the drywall, and therefore never opened. the guy under it caught it in the weirdest way to. it basically fell right onto his back, and he had one hand over it in fornt and one in back, but htanks to him nothing was damaged. anyhow, we redid the anchor and made sure it was fine, and hung it a second time, and its worked wonderfully ever since. its soo cool the way it hangs too. looks very cool!
good luck
jon
