Best time is right after they spawn . Probably around June in most lakes. I put out about 25 lbs min. You can usually catch fish the next day. We use about a sack every day we fish. Scatter some around the boat while fishing.Dump the rest before you leave. The longer you bait an area the better it gets if there is lots of catfish there. We have baited spots for over 3 months and caught hundreds of lbs.