I don't smoke bacon at 225. I cold smoke first, then turn up the temp to 200 to finish. Here's my process for smoking. There are lots of bacon experts on this forum who will have advice too, but this is how I do it (note I do not have a D model).
Cold smoke phase:
Use 5-6 oz chips and/or split slivers of wood for fairly smoky bacon. Hickory, cherry, maple or any combination. Smoke using the cold smoke plate and a pan of ice for 5 hours (20 minutes full blast, 40 minutes off) keeping the ambient box temperature below 100 degrees.
Hot smoke phase:
After 5 hours, remove the cold smoke plate and pan of ice (water at this point). Dump out the water from the drip pan and slide it under the smoker (if you were using the drip pan that came with the SI for ice). Set smoker temp to 200, and continue to smoke to an internal temperature of 150 (will probably take about 2+ hours).