Update on progress....
The latest revision for the intake has been working very well for a couple of weeks now. This is the best working design of everything I've tried. It's simply a 3 ft 1inch PVC pipe that is capped on the end. I drilled several holes for the water to come in all around (and to prevent poor minnows from getting sucked to the pipe). I'd highly recommend this strategy for the intake. See picture below.
Very important....I do water changes of about 15 gallons every week. (3 - five-gallon buckets) I also frequently check for any dead minnows and remove them promptly to keep the water clear and healthy.
Here's a picture of a nice crappie I recently caught using my own minnows kept at home:
I'm now going to move on the collecting and keeping nightcrawlers. My son caught 50+ last night and we are keeping them in worm bedding in a fridge. Who knows, maybe I'll even try keeping crickets over the summer too! There's nothing like having your own bait available.