Reply to Glow in the dark Chroma Cap help?

When I saw DJTT's new Chroma caps I was stoked! Glow in the dark is super cool. The only problem is these things don't last anything other than a short amount of time. Currently I have them under a lamp and they will last around 10 minutes in darkness. I assumed they would last much longer. Anyone else have any problems with them. I believe I am going to send them back. HUGE disappointment. I know glow in the dark is gimmicky but I didn't expect that for 3 dollars a piece from DJTT.