white widow white tip suggestions

Hello all. I got a white widow going on 6 weeks from seed. 2 weeks since last transplant. I just recently started getting white tips on new leaf growth. Fox farm ocean forest soil. Tap water with ph of 6.8. Always let water sit 24hr under light. Havnt used any added nutes from hearing widows don't like much feeding until flower. I was thinking maybe a zinc deficiency which seems rare or maybe a little overwater? Anybody got an opinion? Thanks

Sounds like it happened upon transplanting. Perhaps the soil was a bit too hot and it's adjusting.