How to clean my hull

[ClubMonki]

I use this stuff to get off the scum, but I know it takes away from the gel coat. What do you guys think I should do to wax or prep my hull so it does not stain so easy?
https://www.instacart.com/landing?p...Ny4WHKAmhlgpOtphPdcf_2Nu1X0KBCssaAsrXEALw_wcB