Sacrificial anode on Aluminum boat

[mcjaredsandwich]

I'm in the process of rejuvenating an older model Lowe 16' aluminum. Used it years ago and it sat for several years. Didn't know the dangers of brackish/saltwater and aluminum, found small corrosion marks under bunks and on transom. I filled these pin holes and covered them with JB Weld Waterweld.

After putting in the work of patching, sanding, cleaning, priming and painting, I want to mitigate this potential problem as much as possible. For the aluminum boat owners, where did you place your sacrificial anode, and what size did you use?

I was thinking about installing this one on the transom below the waterline before I get to painting the back.



Thoughts or advice?