Do you have an UPH or PAP? If so I would recommend going a few hours before the waterparks close- the lines are much shorter- but it might not be worth using a plus or paying $30 for 2 hrs.
If you don't have an UPH or PAP, I would probably go on a weekday and get there early to get a good spot. Do the slides first and then later when it gets busier, do the lazy river and wave pool. HTH -Steph