Ive read about growers using 100% perlite,or with vermiculite mixed in for water retention,but never done it myself.
Do some research on it and weigh up the pros and cons.
Ive not seen many growers using it on RIU,but there will be some who could advise you better than me.
Try the search bar on here or Google it,you shud get a fair idea from there.
GL.