u can try but u'll probally not get the effect u expected, if ur decorations have flourescent colors it'll shine but other than that barely noticable, same with gravel if it's dark it won't show on the black light but light like white would give a blue glow my cuz tried that with his 70 gal tank when he put just community fish one was the painted glassfish and well only paint showed on the fish which made it look even worse b/c it actually looked artificial, i've seen a cool black light tank in a lfs near my grandmas house and it was pretty cool but unless ur on acid it's not that interesting looked like something in the back of Spencers Gift storewith all the black light stuff u'll hardly see the fish in just a black light setup even if u don't like theblack light effect u can just use the light in ur room