88 is hot Keaton. Perhaps your critters have acclimated now to that high temperature and therefore aren't showing any ill effects, but I can't help but think that they're being stressed. After all, tropical water temps can get pretty warm as well. But they'd be much better off in the 80 - 82 degree range. I keep my tanks at 80, and this weekend the pump that pushes water through my chiller failed. They were at 88 for about 10 hours or so, and I lost two fish and one coral. I'm lucky it wasn't worse. The least you should do is have a fan in your hood, and a fan blowing air across your sump. That should be enough to lower the temp a few degrees.