I got a fire going last night in my HI300. I started off kinda rough (not enough kindling I am thinking) but finally got a good bed of coals going and got my temps up to 450'ish. At around 10:00pm I tossed in three good sized spits for overnight and got them going really well. Once it settled in and secondaries are blazing away, I checked my temps (600-650) and noticed the secondary tubes in the firebox were starting to glow a little red. Is this to be expected?