Flowers are challenging no matter how you spin it unless they are kept by themselves. If you want to mix flowers with other rays make sure the flowers are the larger of the rays. Flowers are high energy and need to eat a lot to keep from getting skinny but they are also slow eaters so they miss out on a lot of food because other rays will eat it all before they get to it. I have owned both and would recommend jags or other castexi type rays. Ultimately it is up to you on how much of a challenge you want. A 6x6 would only house 3 adults but you could put 5 smaller ones in there. Tiger prices range from around $600 to $1000