Tantalum cap question

[Fuzz Wizard]

I ordered some 1.5uf tantalum capacitors for C16 on the promethium, as I didn't want to do a whole order from Mouser for one cap. After testing a few in my muti-function tester I noticed that they all have some level of Vloss, around 0.3 to 0.5 percent. Are these still safe to use? I'm also curious about the orientation of the cap on the pcb. Which way should the positive leg be facing?

 

[manfesto]

Unless there's been a board revision, I think the Promethium PCB has the polarity for C16 marked on the board, and I've used tantalums every time I've built one without issue (bought a bag of 'em specifically for Promethiums and haven't run out yet).

I can't seem to find an agreed-upon definition of Vloss on the internet (with a *lot* of people saying it's either meaningless or meaningless without context), are you using a Mega328 tester? If so it seems like a leakage-related measurement...