Yellow leaves at bottom. New growth good. How she looking?

I would be a bit concerned with your reservoir temp. You really want to get that down to about 65 at least or try to get it below the temps in your tent. I recommend getting a good look your roots as well. With higher temperature comes more root problems and those you really don't want. See if you have any brown coloration forming on the roots or a smell starting that isn't normal. Even if you think you're safe I would empty your reservoir and refill with some fresh nutes and water. Then add about 10ml hydrogen peroxide to get rid of any bad bacteria or growth that might have started. Hope this helps.