who has had an electrolisis problem with their aluminum components,
or is this a saltwater marine problem.
..thinking about getting an alum rad.

I have one hanging inside the radiators on 2 cars, both of which have Aluminum heads & intake, one has alum rad. Both have anti-freeze & water-wetter in them.
The anode in the car with OEM rad is sacrificing itself much quicker than the alum rad car; possibly because there's less aluminum to attack, but neither car has had any noticeable problems.

Could you tell me where you got got the Zinc Anodes and how did you hang them?

e bay ... zinc anode.
one style installs in your rad drain valve opening.