is this one weighted???

any good suggestions on how to mark your nymphs and streamers that are weighted as opposed to unweighted. i can't tell the difference in my fly box, i don't want to buy another fly box i have too many as it is. i thought about tying 1 strand of flashabou into each nynph as an indicator, any others?

ORIGINAL: D-MAC

How about different thread color for each, say olive unweighted, black weighted....

 
That's how I do it too.  Thread color.

I've done red for weighted, easy to see and adds a bit more attractant in way of color.

After you complete the head of your weighted fly, tie in any other color thread and add a few laps. You can add thread by the hook eye or back close to the body. 'Tis but the work of a moment. Then add a coat of good ol' Sally H. When you open your box, the weighted flies are the ones that have a head stripe.
 
 

Drop it in the water, If it floats for a moment it is not weighted.  If it goes to the bottom and you lose it... that one was weighted. 

My motto red is lead. Just a little red head is all you need.