You can create a FreeRADIUS server with username/password credentials (and possibly even matching MAC address?),
and define an 802.1x WLAN on your wireless. Clients need to authenticate the first time they use the network, and can
cache/save those credentials for seamless access next time.
If you have created a Captive portal in a Linux server, you need to define a HotSpot service on Ruckus, and I do not think
your clients can save their logins from a web page access method, or have a MAC auth pre-authentication.