1/4" and shrinking-need help!

[candleessence]

Im kinda confused & Im hoping someone can help. Im using J300 w/ 62z for this jar. I start out w/ 1/4" length for the wick (even use a ruler ) The 1st three burns or so I can keep the wick @ this length without any soot. As I keep burning the candle though I need to keep trimming the wick smaller & smaller so it doesn't soot. Does this mean that the wick Im using is too big? Im posting a picture b/c to me this is what is a 1/4" but in reality it will burn perfectly if I trim it smaller. Looking @ this does the wick length seem to big to ya'll? Or should I try to go down one size so the wick length shoud be more this size? TIA