Nodak7,
Bill's comments about hard/ablative paint(s) are well taken.
I used Petit Trinadad for many years. I worked well to inhibit growth, but the "build up" problem became severe. A few years ago, I stripped all the old (hard) paint off. Since then, I have used hard paint (Trinadad SR) on the keel and rudder. I think it's more resistant to fouling than ablative, the hard paint rubs off less easily when you go aground, and any extra build up weight down low isn't really a problem.
I use ablative on the hull, with several coats along the waterline.
Like everyone else, I've tried lots of different things on the prop and shaft. My preference has evolved to using Petit "Zinc Coat Barnacle Barrier". It seems to work (for me) better than anything else. After it dries on the prop and shaft I smear a heavy layer of (generic) Desitin ointment over it.
I know, sounds "mickey mouse", but, the zinc oxide ointment stays on for a few months and very much inhibits all growth, before it finally gets "blown" off motoring. ... It's inexpensive, helps further delay prop/shaft fouling, and I only get laughed at till the boat goes back in the water ...