Ok I have a question. I have a 10gal with a hood and I have a 55gal with a glass top. If I leave my tank open with no top how will that effect my house? Will I have trouble with mold or mildew? The reason I ask is that I am getting ANOTHER 55gal this weekend... yes I know.... MTS is really starting to kill me. But I am trying to figure out if I need a hood for it or just leave it open with a "halo" light or something like that?