<span class="link_user">@CRiSPrGrow</span>, tabs were not close to the plant. I used promix veg and herb with 50% perlite. Still scratching my head because Iāve never burned seedling with that soil before.
<span class="link_user">@Jayou413</span>, IMHO the tabs themselves wouldn't really have started to dissolve that quickly so I think the soil was too hot or the tab was too close to the plant perhaps?