Hi there. First post on here and just wanted to get some clarity on a particular issue. I currently have a glass tank (24 inc long, 12 in wide, 12 in high) set up with aluminum foil and cardboard lining the top. My coolside has a temp of 79-80 and my hot side has an ambient temp of 89-90 and a surface temp of 90-92 directly over the uth. Humidity stays at 60-64%. To achieve these temperatures and humidity, I am using a 40 watt black light bulb with the water dish placed directly under it. My concern is that the water is too warm (88 degrees measured with a thermometer probe). I was hoping to eliminate the heat lamp, since my ambient temp stays at 79-80 degrees without it. Will a uth be a sufficient hot spot without a heat lamp? Or do you all think I should keep things as they are?

Thanks for the help!

PS: heat lamp and uth controlled by their own lamp dimmer