With teens I would head to the East Coast. They will love Ron Jons, the waves, boogey boarding, watching surfers, etc. Your kids have seen the Gulf now time to show them an ocean. It is a totally different experience. Check out the beach at the pier, Erna Nixon Park, or even come farther South to the Melbourne area. Here (the Space Coast) except for in city parks in a couple places, the parking is free. All county beach accesses or parks are free. No private beaches even at the hotels. The county parks all have restrooms/changing areas and many have food stands. The beaches are never crowded since we have 72 miles of beach to explore.
Remember all water is clear, it is just the position of the sun,clouds, and the bottom that gives free flowing water a color. The East coast water has all the colors depending on the day and time you are there.
We rarely have a red tide on the East Coast near Cocoa Beach. Can only remember once in the 38 years I have lived on the Space Coast.