how do I keep temps down with out a humidifier or...

If your ambient temperatures are too high, there is very little you can do. I mean if the weather is really warm and it's 28 °C (82°F), the only way to really lower the temps inside the tent will be with an AC unit. If that is not the case and the ambient temperatures are much lower than inside the tent, you need to increase the exhaust. What does help is to avoid switching the lights on during the hotter parts of the day, I myself would use lights off between 12 pm and 6 pm which is the hotter part of the day and when switching to 12/12, I would switch the lights on during the night, avoiding the day altogether. I hope that helps.