Hi All, I have a 10 gal that I have an older style lid with 2 50w bulb type lights. Thye give off much more heat (and much less light) than a typical LED or T5/8 flourescent bulb. I have noticed that the temp in my tank is higher than where I wanted it and sits at about 79.8*F, though I wanted around 78 for some RCS and some cories. I have turned off the light to make sure that the heater isn't somehow turned up, but here is my question, if I decide to leave it where it is, will the cooling overnight be a problem? should I try to set teh heater for 80* or so? Another question, what hardness level is good for these guys? My water is naturally quite hard out of the tap (about 12*), I was told cories prefer about 8* is this true? Do I need to soften my water for my cories to thrive?