Hi Lex, I only use a small batch of lump to start and get a good bed of coals going. Then I use hardwood. For the butts I used a mix of cherry and apple that I have on hand. They are splits about 8-10 inches in length, no wider than a soda can. Usually I have to add a split about every 45 minutes or so. I have done a couple of runs with only lump charcoal. It works well, but you still need to add periodically to maintain temps. I prefer to smoke with wood only. I am not saying that the final product is better, but I just enjoy doing it that way :) Hope this helps!!!